* Re: [RFC PATCH v5 1/1] Add dm verity root hash pkcs7 sig validation.
From: Milan Broz @ 2019-06-27 12:17 UTC (permalink / raw)
To: Jaskaran Khurana, linux-security-module, linux-kernel,
linux-integrity, linux-fsdevel
Cc: agk, snitzer, dm-devel, jmorris, scottsh, ebiggers, mpatocka
In-Reply-To: <20190619191048.20365-2-jaskarankhurana@linux.microsoft.com>
Hi,
I tried to test test the patch, two comments below.
On 19/06/2019 21:10, Jaskaran Khurana wrote:
> The verification is to support cases where the roothash is not secured by
> Trusted Boot, UEFI Secureboot or similar technologies.
> One of the use cases for this is for dm-verity volumes mounted after boot,
> the root hash provided during the creation of the dm-verity volume has to
> be secure and thus in-kernel validation implemented here will be used
> before we trust the root hash and allow the block device to be created.
>
> The signature being provided for verification must verify the root hash and
> must be trusted by the builtin keyring for verification to succeed.
>
> The hash is added as a key of type "user" and the description is passed to
> the kernel so it can look it up and use it for verification.
>
> Kernel commandline parameter will indicate whether to check (only if
> specified) or force (for all dm verity volumes) roothash signature
> verification.
>
> Kernel commandline: dm_verity.verify_sig=1 or 2 for check/force root hash
> signature validation respectively.
1) I think the switch should be just boolean - enforce signatures for all dm-verity targets
(with default to false/off).
The rest should be handled by simple logic - if the root_hash_sig_key_desc option
is specified, the signature MUST be validated in the constructor, all errors should cause
failure (bad reference in keyring, bad signature, etc).
(Now it ignores for example bad reference to the keyring, this is quite misleading.)
If a user wants to activate a dm-verity device without a signature, just remove
optional argument referencing the signature.
(This is not possible with dm_verity.verify_sig set to true/on.)
2) All DM targets must provide the same mapping table status ("dmsetup table"
command) as initially configured.
The output of the command should be directly usable as mapping table constructor.
Your patch is missing that part, I tried to fix it, add-on patch is here
https://git.kernel.org/pub/scm/linux/kernel/git/mbroz/linux.git/commit/?h=dm-cryptsetup&id=a26c10806f5257e255b6a436713127e762935ad3
(feel free to fold it in your patch)
Thanks,
Milan
^ permalink raw reply
* Re: [PATCH v8 1/2] mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
From: Alexander Potapenko @ 2019-06-27 10:05 UTC (permalink / raw)
To: Andrew Morton
Cc: Christoph Lameter, Kees Cook, Masahiro Yamada, Michal Hocko,
James Morris, Serge E. Hallyn, Nick Desaulniers,
Kostya Serebryany, Dmitry Vyukov, Sandeep Patil, Laura Abbott,
Randy Dunlap, Jann Horn, Mark Rutland, Marco Elver, Qian Cai,
Linux Memory Management List, linux-security-module,
Kernel Hardening
In-Reply-To: <20190626162835.0947684d36ef01639f969232@linux-foundation.org>
On Thu, Jun 27, 2019 at 1:28 AM Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Wed, 26 Jun 2019 14:19:42 +0200 Alexander Potapenko <glider@google.com> wrote:
>
> > v8:
> > - addressed comments by Michal Hocko: revert kernel/kexec_core.c and
> > apply initialization in dma_pool_free()
> > - disable init_on_alloc/init_on_free if slab poisoning or page
> > poisoning are enabled, as requested by Qian Cai
> > - skip the redzone when initializing a freed heap object, as requested
> > by Qian Cai and Kees Cook
> > - use s->offset to address the freeptr (suggested by Kees Cook)
> > - updated the patch description, added Signed-off-by: tag
>
> v8 failed to incorporate
>
> https://ozlabs.org/~akpm/mmots/broken-out/mm-security-introduce-init_on_alloc=1-and-init_on_free=1-boot-options-fix.patch
> and
> https://ozlabs.org/~akpm/mmots/broken-out/mm-security-introduce-init_on_alloc=1-and-init_on_free=1-boot-options-fix-2.patch
>
> it's conventional to incorporate such fixes when preparing a new
> version of a patch.
>
Ah, sorry about that.
I'll probably send out v9 with proper poison handling and will pick
those two patches as well.
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
^ permalink raw reply
* Re: [PATCH v8 1/2] mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
From: Alexander Potapenko @ 2019-06-27 8:18 UTC (permalink / raw)
To: Qian Cai
Cc: Andrew Morton, Christoph Lameter, Kees Cook, Masahiro Yamada,
Michal Hocko, James Morris, Serge E. Hallyn, Nick Desaulniers,
Kostya Serebryany, Dmitry Vyukov, Sandeep Patil, Laura Abbott,
Randy Dunlap, Jann Horn, Mark Rutland, Marco Elver,
Linux Memory Management List, linux-security-module,
Kernel Hardening, clang-built-linux
In-Reply-To: <1561572949.5154.81.camel@lca.pw>
On Wed, Jun 26, 2019 at 8:15 PM Qian Cai <cai@lca.pw> wrote:
>
> On Wed, 2019-06-26 at 14:19 +0200, Alexander Potapenko wrote:
> > The new options are needed to prevent possible information leaks and
> > make control-flow bugs that depend on uninitialized values more
> > deterministic.
> >
> > This is expected to be on-by-default on Android and Chrome OS. And it
> > gives the opportunity for anyone else to use it under distros too via
> > the boot args. (The init_on_free feature is regularly requested by
> > folks where memory forensics is included in their threat models.)
> >
> > init_on_alloc=1 makes the kernel initialize newly allocated pages and heap
> > objects with zeroes. Initialization is done at allocation time at the
> > places where checks for __GFP_ZERO are performed.
> >
> > init_on_free=1 makes the kernel initialize freed pages and heap objects
> > with zeroes upon their deletion. This helps to ensure sensitive data
> > doesn't leak via use-after-free accesses.
> >
> > Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator
> > returns zeroed memory. The two exceptions are slab caches with
> > constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never
> > zero-initialized to preserve their semantics.
> >
> > Both init_on_alloc and init_on_free default to zero, but those defaults
> > can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and
> > CONFIG_INIT_ON_FREE_DEFAULT_ON.
> >
> > If either SLUB poisoning or page poisoning is enabled, we disable
> > init_on_alloc and init_on_free so that initialization doesn't interfere
> > with debugging.
> >
> > Slowdown for the new features compared to init_on_free=0,
> > init_on_alloc=0:
> >
> > hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%)
> > hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%)
> >
> > Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%)
> > Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%)
> > Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%)
> > Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%)
> >
> > The slowdown for init_on_free=0, init_on_alloc=0 compared to the
> > baseline is within the standard error.
> >
> > The new features are also going to pave the way for hardware memory
> > tagging (e.g. arm64's MTE), which will require both on_alloc and on_free
> > hooks to set the tags for heap objects. With MTE, tagging will have the
> > same cost as memory initialization.
> >
> > Although init_on_free is rather costly, there are paranoid use-cases where
> > in-memory data lifetime is desired to be minimized. There are various
> > arguments for/against the realism of the associated threat models, but
> > given that we'll need the infrastructure for MTE anyway, and there are
> > people who want wipe-on-free behavior no matter what the performance cost,
> > it seems reasonable to include it in this series.
> >
> > Signed-off-by: Alexander Potapenko <glider@google.com>
> > Acked-by: Kees Cook <keescook@chromium.org>
> > To: Andrew Morton <akpm@linux-foundation.org>
> > To: Christoph Lameter <cl@linux.com>
> > To: Kees Cook <keescook@chromium.org>
> > Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> > Cc: Michal Hocko <mhocko@kernel.org>
> > Cc: James Morris <jmorris@namei.org>
> > Cc: "Serge E. Hallyn" <serge@hallyn.com>
> > Cc: Nick Desaulniers <ndesaulniers@google.com>
> > Cc: Kostya Serebryany <kcc@google.com>
> > Cc: Dmitry Vyukov <dvyukov@google.com>
> > Cc: Sandeep Patil <sspatil@android.com>
> > Cc: Laura Abbott <labbott@redhat.com>
> > Cc: Randy Dunlap <rdunlap@infradead.org>
> > Cc: Jann Horn <jannh@google.com>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: Marco Elver <elver@google.com>
> > Cc: Qian Cai <cai@lca.pw>
> > Cc: linux-mm@kvack.org
> > Cc: linux-security-module@vger.kernel.org
> > Cc: kernel-hardening@lists.openwall.com
> > Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> > ---
> > v2:
> > - unconditionally initialize pages in kernel_init_free_pages()
> > - comment from Randy Dunlap: drop 'default false' lines from
> > Kconfig.hardening
> > v3:
> > - don't call kernel_init_free_pages() from memblock_free_pages()
> > - adopted some Kees' comments for the patch description
> > v4:
> > - use NULL instead of 0 in slab_alloc_node() (found by kbuild test robot)
> > - don't write to NULL object in slab_alloc_node() (found by Android
> > testing)
> > v5:
> > - adjusted documentation wording as suggested by Kees
> > - disable SLAB_POISON if auto-initialization is on
> > - don't wipe RCU cache allocations made without __GFP_ZERO
> > - dropped SLOB support
> > v7:
> > - rebase the patch, added the Acked-by: tag
> > v8:
> > - addressed comments by Michal Hocko: revert kernel/kexec_core.c and
> > apply initialization in dma_pool_free()
> > - disable init_on_alloc/init_on_free if slab poisoning or page
> > poisoning are enabled, as requested by Qian Cai
> > - skip the redzone when initializing a freed heap object, as requested
> > by Qian Cai and Kees Cook
> > - use s->offset to address the freeptr (suggested by Kees Cook)
> > - updated the patch description, added Signed-off-by: tag
> > ---
> > .../admin-guide/kernel-parameters.txt | 9 +++
> > drivers/infiniband/core/uverbs_ioctl.c | 2 +-
> > include/linux/mm.h | 22 ++++++
> > mm/dmapool.c | 4 +-
> > mm/page_alloc.c | 71 +++++++++++++++++--
> > mm/slab.c | 16 ++++-
> > mm/slab.h | 19 +++++
> > mm/slub.c | 43 +++++++++--
> > net/core/sock.c | 2 +-
> > security/Kconfig.hardening | 29 ++++++++
> > 10 files changed, 199 insertions(+), 18 deletions(-)
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt
> > b/Documentation/admin-guide/kernel-parameters.txt
> > index 138f6664b2e2..84ee1121a2b9 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -1673,6 +1673,15 @@
> >
> > initrd= [BOOT] Specify the location of the initial
> > ramdisk
> >
> > + init_on_alloc= [MM] Fill newly allocated pages and heap
> > objects with
> > + zeroes.
> > + Format: 0 | 1
> > + Default set by CONFIG_INIT_ON_ALLOC_DEFAULT_ON.
> > +
> > + init_on_free= [MM] Fill freed pages and heap objects with
> > zeroes.
> > + Format: 0 | 1
> > + Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
> > +
> > init_pkru= [x86] Specify the default memory protection keys
> > rights
> > register contents for all processes. 0x55555554 by
> > default (disallow access to all but pkey 0). Can
> > diff --git a/drivers/infiniband/core/uverbs_ioctl.c
> > b/drivers/infiniband/core/uverbs_ioctl.c
> > index 829b0c6944d8..61758201d9b2 100644
> > --- a/drivers/infiniband/core/uverbs_ioctl.c
> > +++ b/drivers/infiniband/core/uverbs_ioctl.c
> > @@ -127,7 +127,7 @@ __malloc void *_uverbs_alloc(struct uverbs_attr_bundle
> > *bundle, size_t size,
> > res = (void *)pbundle->internal_buffer + pbundle->internal_used;
> > pbundle->internal_used =
> > ALIGN(new_used, sizeof(*pbundle->internal_buffer));
> > - if (flags & __GFP_ZERO)
> > + if (want_init_on_alloc(flags))
> > memset(res, 0, size);
> > return res;
> > }
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index dd0b5f4e1e45..96be2604f313 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2696,6 +2696,28 @@ static inline void kernel_poison_pages(struct page
> > *page, int numpages,
> > int enable) { }
> > #endif
> >
> > +#ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
> > +DECLARE_STATIC_KEY_TRUE(init_on_alloc);
> > +#else
> > +DECLARE_STATIC_KEY_FALSE(init_on_alloc);
> > +#endif
> > +static inline bool want_init_on_alloc(gfp_t flags)
> > +{
> > + if (static_branch_unlikely(&init_on_alloc))
> > + return true;
> > + return flags & __GFP_ZERO;
> > +}
> > +
> > +#ifdef CONFIG_INIT_ON_FREE_DEFAULT_ON
> > +DECLARE_STATIC_KEY_TRUE(init_on_free);
> > +#else
> > +DECLARE_STATIC_KEY_FALSE(init_on_free);
> > +#endif
> > +static inline bool want_init_on_free(void)
> > +{
> > + return static_branch_unlikely(&init_on_free);
> > +}
> > +
> > extern bool _debug_pagealloc_enabled;
> >
> > static inline bool debug_pagealloc_enabled(void)
>
> Do those really necessary need to be static keys?
Yes. Initially they weren't, but using static branches saved us a few %%.
> Adding either init_on_free=0 or init_on_alloc=0 to the kernel cmdline will
> generate a warning with kernels built with clang.
Looks like Kees has taken care of this issue in his "arm64: Move
jump_label_init() before parse_early_param()"
Thanks Kees!
> [ 0.000000] static_key_disable(): static key 'init_on_free+0x0/0x4' used
> before call to jump_label_init()
> [ 0.000000] WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:317
> early_init_on_free+0x1c0/0x200
> [ 0.000000] Modules linked in:
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc6-next-20190626+
> #9
> [ 0.000000] pstate: 60000089 (nZCv daIf -PAN -UAO)
> [ 0.000000] pc : early_init_on_free+0x1c0/0x200
> [ 0.000000] lr : early_init_on_free+0x1c0/0x200
> [ 0.000000] sp : ffff100012c07df0
> [ 0.000000] x29: ffff100012c07e20 x28: ffff1000110a01ec
> [ 0.000000] x27: 000000000000005f x26: ffff100011716cd0
> [ 0.000000] x25: ffff100010d36166 x24: ffff100010d3615d
> [ 0.000000] x23: ffff100010d364b5 x22: ffff1000117164a0
> [ 0.000000] x21: 0000000000000000 x20: 0000000000000000
> [ 0.000000] x19: 0000000000000000 x18: 000000000000002e
> [ 0.000000] x17: 000000000000000f x16: 0000000000000040
> [ 0.000000] x15: 0000000000000000 x14: 6c61632065726f66
> [ 0.000000] x13: 6562206465737520 x12: 273478302f307830
> [ 0.000000] x11: 0000000000000000 x10: 0000000000000000
> [ 0.000000] x9 : 0000000000000000 x8 : 0000000000000000
> [ 0.000000] x7 : 6d756a206f74206c x6 : ffff100014426625
> [ 0.000000] x5 : ffff100012c07b28 x4 : 0000000000000007
> [ 0.000000] x3 : ffff1000101aadf4 x2 : 0000000000000001
> [ 0.000000] x1 : 0000000000000001 x0 : 000000000000005d
> [ 0.000000] Call trace:
> [ 0.000000] early_init_on_free+0x1c0/0x200
> [ 0.000000] do_early_param+0xd0/0x104
> [ 0.000000] parse_args+0x1f0/0x524
> [ 0.000000] parse_early_param+0x70/0x8c
> [ 0.000000] setup_arch+0xa8/0x268
> [ 0.000000] start_kernel+0x80/0x560
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg
^ permalink raw reply
* Re: [PATCH v8 1/2] mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
From: Michal Hocko @ 2019-06-27 6:15 UTC (permalink / raw)
To: Kees Cook
Cc: Qian Cai, Catalin Marinas, Ard Biesheuvel, Alexander Potapenko,
Andrew Morton, Christoph Lameter, Masahiro Yamada, James Morris,
Serge E. Hallyn, Nick Desaulniers, Kostya Serebryany,
Dmitry Vyukov, Sandeep Patil, Laura Abbott, Randy Dunlap,
Jann Horn, Mark Rutland, Marco Elver, linux-mm,
linux-security-module, kernel-hardening, clang-built-linux
In-Reply-To: <201906261303.020ADC9@keescook>
On Wed 26-06-19 13:23:34, Kees Cook wrote:
> On Wed, Jun 26, 2019 at 02:15:49PM -0400, Qian Cai wrote:
> > On Wed, 2019-06-26 at 14:19 +0200, Alexander Potapenko wrote:
> > > Both init_on_alloc and init_on_free default to zero, but those defaults
> > > can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and
> > > CONFIG_INIT_ON_FREE_DEFAULT_ON.
> > > [...]
> > > +static int __init early_init_on_alloc(char *buf)
> > > +{
> > > + int ret;
> > > + bool bool_result;
> > > +
> > > + if (!buf)
> > > + return -EINVAL;
> > > + ret = kstrtobool(buf, &bool_result);
> > > + if (bool_result)
> > > + static_branch_enable(&init_on_alloc);
> > > + else
> > > + static_branch_disable(&init_on_alloc);
> > > + return ret;
> > > +}
> > > +early_param("init_on_alloc", early_init_on_alloc);
> >
> > Do those really necessary need to be static keys?
> >
> > Adding either init_on_free=0 or init_on_alloc=0 to the kernel cmdline will
> > generate a warning with kernels built with clang.
> >
> > [ 0.000000] static_key_disable(): static key 'init_on_free+0x0/0x4' used
> > before call to jump_label_init()
> > [ 0.000000] WARNING: CPU: 0 PID: 0 at ./include/linux/jump_label.h:317
> > early_init_on_free+0x1c0/0x200
> > [ 0.000000] Modules linked in:
> > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc6-next-20190626+
> > #9
> > [ 0.000000] pstate: 60000089 (nZCv daIf -PAN -UAO)
>
> I think the issue here is that arm64 doesn't initialize static keys
> early enough.
This sounds familiar: http://lkml.kernel.org/r/CABXOdTd-cqHM_feAO1tvwn4Z=kM6WHKYAbDJ7LGfMvRPRPG7GA@mail.gmail.com
--
Michal Hocko
SUSE Labs
^ permalink raw reply
* Re: [PATCH V34 09/29] kexec_file: Restrict at runtime if the kernel is locked down
From: James Morris @ 2019-06-27 4:59 UTC (permalink / raw)
To: Matthew Garrett
Cc: linux-security-module, linux-kernel, linux-api, Jiri Bohac,
David Howells, Matthew Garrett, kexec
In-Reply-To: <20190622000358.19895-10-matthewgarrett@google.com>
On Fri, 21 Jun 2019, Matthew Garrett wrote:
> From: Jiri Bohac <jbohac@suse.cz>
>
> When KEXEC_SIG is not enabled, kernel should not load images through
> kexec_file systemcall if the kernel is locked down.
This is not a criticism of the patch but a related issue which I haven't
seen discussed (apologies if it has).
If signed code is loaded into ring 0, verified by the kernel, then
executed, you still lose your secure/trusted/verified boot state. If the
currently running kernel has been runtime-compromised, any signature
verification performed by the kernel cannot be trusted.
This problem is out of scope for the lockdown threat model (which
naturally cannot include a compromised kernel), but folk should be aware
that signature-verified kexec does not provide equivalent assurance to a
full reboot on a secure-boot system.
Potential mitigations here include runtime integrity verification of the
kernel via a separate security monitor (hypervisor, SMM, TEE etc.) or some
kind of platform support for kexec verification.
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH v4 00/23] LSM: Module stacking for AppArmor
From: James Morris @ 2019-06-27 4:10 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, Kees Cook,
John Johansen, Tetsuo Handa, Paul Moore, Stephen Smalley
In-Reply-To: <alpine.LRH.2.21.1906271344480.16512@namei.org>
On Thu, 27 Jun 2019, James Morris wrote:
> Confirming there's no oops when Tomoyo is un-selected in the kernel
> config.
n/m, the problem is still there.
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH v4 17/23] LSM: Use lsmcontext in security_secid_to_secctx
From: Kees Cook @ 2019-06-27 3:53 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, jmorris, linux-security-module, selinux,
john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-18-casey@schaufler-ca.com>
On Wed, Jun 26, 2019 at 12:22:28PM -0700, Casey Schaufler wrote:
> Replace the (secctx,seclen) pointer pair with a single
> lsmcontext pointer to allow return of the LSM identifier
> along with the context and context length. This allows
> security_release_secctx() to know how to release the
> context. Callers have been modified to use or save the
> returned data from the new structure.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
> drivers/android/binder.c | 24 ++++++---------
> include/linux/security.h | 4 +--
> include/net/scm.h | 9 ++----
> kernel/audit.c | 29 +++++++-----------
> kernel/auditsc.c | 31 +++++++------------
> net/ipv4/ip_sockglue.c | 7 ++---
> net/netfilter/nf_conntrack_netlink.c | 14 +++++----
> net/netfilter/nf_conntrack_standalone.c | 7 ++---
> net/netfilter/nfnetlink_queue.c | 5 +++-
> net/netlabel/netlabel_unlabeled.c | 40 ++++++++-----------------
> net/netlabel/netlabel_user.c | 7 ++---
> security/security.c | 9 ++++--
> 12 files changed, 72 insertions(+), 114 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 89e574be34cc..5d417a7b9bb3 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -2874,9 +2874,7 @@ static void binder_transaction(struct binder_proc *proc,
> binder_size_t last_fixup_min_off = 0;
> struct binder_context *context = proc->context;
> int t_debug_id = atomic_inc_return(&binder_last_id);
> - char *secctx = NULL;
> - u32 secctx_sz = 0;
> - struct lsmcontext scaff; /* scaffolding */
> + struct lsmcontext lsmctx;
As James found, this needs to be zero initialized:
struct lsmcontext lsmctx = { };
otherwise...
>
> e = binder_transaction_log_add(&binder_transaction_log);
> e->debug_id = t_debug_id;
> @@ -3123,14 +3121,14 @@ static void binder_transaction(struct binder_proc *proc,
> struct lsmblob blob;
>
> security_task_getsecid(proc->tsk, &blob);
> - ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> + ret = security_secid_to_secctx(&blob, &lsmctx);
> if (ret) {
> return_error = BR_FAILED_REPLY;
> return_error_param = ret;
> return_error_line = __LINE__;
> goto err_get_secctx_failed;
> }
> - extra_buffers_size += ALIGN(secctx_sz, sizeof(u64));
> + extra_buffers_size += ALIGN(lsmctx.len, sizeof(u64));
> }
>
> trace_binder_transaction(reply, t, target_node);
> @@ -3149,19 +3147,17 @@ static void binder_transaction(struct binder_proc *proc,
> t->buffer = NULL;
> goto err_binder_alloc_buf_failed;
> }
> - if (secctx) {
> + if (lsmctx.context) {
This test may read stack trash.
Unless you built with the stack zeroing plugin or compiler. ;)
-Kees
> size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
> ALIGN(tr->offsets_size, sizeof(void *)) +
> ALIGN(extra_buffers_size, sizeof(void *)) -
> - ALIGN(secctx_sz, sizeof(u64));
> + ALIGN(lsmctx.len, sizeof(u64));
>
> t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
> binder_alloc_copy_to_buffer(&target_proc->alloc,
> t->buffer, buf_offset,
> - secctx, secctx_sz);
> - lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> - security_release_secctx(&scaff);
> - secctx = NULL;
> + lsmctx.context, lsmctx.len);
> + security_release_secctx(&lsmctx);
> }
> t->buffer->debug_id = t->debug_id;
> t->buffer->transaction = t;
> @@ -3481,10 +3477,8 @@ static void binder_transaction(struct binder_proc *proc,
> t->buffer->transaction = NULL;
> binder_alloc_free_buf(&target_proc->alloc, t->buffer);
> err_binder_alloc_buf_failed:
> - if (secctx) {
> - lsmcontext_init(&scaff, secctx, secctx_sz, 0);
> - security_release_secctx(&scaff);
> - }
> + if (lsmctx.context)
> + security_release_secctx(&lsmctx);
> err_get_secctx_failed:
> kfree(tcomplete);
> binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 046012a7255f..7255825aa697 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -481,7 +481,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> size_t size);
> int security_netlink_send(struct sock *sk, struct sk_buff *skb);
> int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp);
> int security_secctx_to_secid(const char *secdata, u32 seclen,
> struct lsmblob *blob);
> void security_release_secctx(struct lsmcontext *cp);
> @@ -1263,7 +1263,7 @@ static inline int security_ismaclabel(const char *name)
> }
>
> static inline int security_secid_to_secctx(struct lsmblob *blob,
> - char **secdata, u32 *seclen)
> + struct lsmcontext *cp)
> {
> return -EOPNOTSUPP;
> }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 6c7c3c229e4a..4a6ad8caf423 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -93,17 +93,14 @@ static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
> static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
> {
> struct lsmcontext context;
> - char *secdata;
> - u32 seclen;
> int err;
>
> if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> - err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> - &seclen);
> + err = security_secid_to_secctx(&scm->lsmblob, &context);
>
> if (!err) {
> - put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> - lsmcontext_init(&context, secdata, seclen, 0);/*scaffolding*/
> + put_cmsg(msg, SOL_SOCKET, SCM_SECURITY,
> + context.len, context.context);
> security_release_secctx(&context);
> }
> }
> diff --git a/kernel/audit.c b/kernel/audit.c
> index f844a2a642e6..436c23429319 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1191,9 +1191,8 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
> struct audit_buffer *ab;
> u16 msg_type = nlh->nlmsg_type;
> struct audit_sig_info *sig_data;
> - char *ctx = NULL;
> u32 len;
> - struct lsmcontext scaff; /* scaffolding */
> + struct lsmcontext context;
>
> err = audit_netlink_ok(skb, msg_type);
> if (err)
> @@ -1431,25 +1430,22 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
> case AUDIT_SIGNAL_INFO:
> len = 0;
> if (lsmblob_is_set(&audit_sig_lsm)) {
> - err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> - &len);
> + err = security_secid_to_secctx(&audit_sig_lsm,
> + &context);
> if (err)
> return err;
> }
> sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
> if (!sig_data) {
> - if (lsmblob_is_set(&audit_sig_lsm)) {
> - lsmcontext_init(&scaff, ctx, len, 0);
> - security_release_secctx(&scaff);
> - }
> + if (lsmblob_is_set(&audit_sig_lsm))
> + security_release_secctx(&context);
> return -ENOMEM;
> }
> sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
> sig_data->pid = audit_sig_pid;
> if (lsmblob_is_set(&audit_sig_lsm)) {
> - memcpy(sig_data->ctx, ctx, len);
> - lsmcontext_init(&scaff, ctx, len, 0);
> - security_release_secctx(&scaff);
> + memcpy(sig_data->ctx, context.context, context.len);
> + security_release_secctx(&context);
> }
> audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
> sig_data, sizeof(*sig_data) + len);
> @@ -2074,26 +2070,23 @@ void audit_log_key(struct audit_buffer *ab, char *key)
>
> int audit_log_task_context(struct audit_buffer *ab)
> {
> - char *ctx = NULL;
> - unsigned len;
> int error;
> struct lsmblob blob;
> - struct lsmcontext scaff; /* scaffolding */
> + struct lsmcontext context;
>
> security_task_getsecid(current, &blob);
> if (!lsmblob_is_set(&blob))
> return 0;
>
> - error = security_secid_to_secctx(&blob, &ctx, &len);
> + error = security_secid_to_secctx(&blob, &context);
> if (error) {
> if (error != -EINVAL)
> goto error_path;
> return 0;
> }
>
> - audit_log_format(ab, " subj=%s", ctx);
> - lsmcontext_init(&scaff, ctx, len, 0);
> - security_release_secctx(&scaff);
> + audit_log_format(ab, " subj=%s", context.context);
> + security_release_secctx(&context);
> return 0;
>
> error_path:
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 9fab0e7d90c3..0478680cd0a8 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -943,9 +943,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> struct lsmblob *blob, char *comm)
> {
> struct audit_buffer *ab;
> - struct lsmcontext lsmcxt;
> - char *ctx = NULL;
> - u32 len;
> + struct lsmcontext lsmctx;
> int rc = 0;
>
> ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> @@ -956,13 +954,12 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> from_kuid(&init_user_ns, auid),
> from_kuid(&init_user_ns, uid), sessionid);
> if (lsmblob_is_set(blob)) {
> - if (security_secid_to_secctx(blob, &ctx, &len)) {
> + if (security_secid_to_secctx(blob, &lsmctx)) {
> audit_log_format(ab, " obj=(none)");
> rc = 1;
> } else {
> - audit_log_format(ab, " obj=%s", ctx);
> - lsmcontext_init(&lsmcxt, ctx, len, 0); /*scaffolding*/
> - security_release_secctx(&lsmcxt);
> + audit_log_format(ab, " obj=%s", lsmctx.context);
> + security_release_secctx(&lsmctx);
> }
> }
> audit_log_format(ab, " ocomm=");
> @@ -1174,7 +1171,6 @@ static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
>
> static void show_special(struct audit_context *context, int *call_panic)
> {
> - struct lsmcontext lsmcxt;
> struct audit_buffer *ab;
> int i;
>
> @@ -1198,17 +1194,15 @@ static void show_special(struct audit_context *context, int *call_panic)
> from_kgid(&init_user_ns, context->ipc.gid),
> context->ipc.mode);
> if (osid) {
> - char *ctx = NULL;
> - u32 len;
> + struct lsmcontext lsmcxt;
> struct lsmblob blob;
>
> lsmblob_init(&blob, osid);
> - if (security_secid_to_secctx(&blob, &ctx, &len)) {
> + if (security_secid_to_secctx(&blob, &lsmcxt)) {
> audit_log_format(ab, " osid=%u", osid);
> *call_panic = 1;
> } else {
> - audit_log_format(ab, " obj=%s", ctx);
> - lsmcontext_init(&lsmcxt, ctx, len, 0);
> + audit_log_format(ab, " obj=%s", lsmcxt.context);
> security_release_secctx(&lsmcxt);
> }
> }
> @@ -1353,20 +1347,17 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
> MAJOR(n->rdev),
> MINOR(n->rdev));
> if (n->osid != 0) {
> - char *ctx = NULL;
> - u32 len;
> struct lsmblob blob;
> - struct lsmcontext lsmcxt;
> + struct lsmcontext lsmctx;
>
> lsmblob_init(&blob, n->osid);
> - if (security_secid_to_secctx(&blob, &ctx, &len)) {
> + if (security_secid_to_secctx(&blob, &lsmctx)) {
> audit_log_format(ab, " osid=%u", n->osid);
> if (call_panic)
> *call_panic = 2;
> } else {
> - audit_log_format(ab, " obj=%s", ctx);
> - lsmcontext_init(&lsmcxt, ctx, len, 0); /* scaffolding */
> - security_release_secctx(&lsmcxt);
> + audit_log_format(ab, " obj=%s", lsmctx.context);
> + security_release_secctx(&lsmctx);
> }
> }
>
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 7834c357b60b..80ae0c5a1301 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -132,20 +132,17 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
> {
> struct lsmcontext context;
> struct lsmblob lb;
> - char *secdata;
> - u32 seclen;
> int err;
>
> err = security_socket_getpeersec_dgram(NULL, skb, &lb);
> if (err)
> return;
>
> - err = security_secid_to_secctx(&lb, &secdata, &seclen);
> + err = security_secid_to_secctx(&lb, &context);
> if (err)
> return;
>
> - put_cmsg(msg, SOL_IP, SCM_SECURITY, seclen, secdata);
> - lsmcontext_init(&context, secdata, seclen, 0); /* scaffolding */
> + put_cmsg(msg, SOL_IP, SCM_SECURITY, context.len, context.context);
> security_release_secctx(&context);
> }
>
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 6954e6600583..403307ff0fff 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -328,13 +328,12 @@ static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct)
> static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
> {
> struct nlattr *nest_secctx;
> - int len, ret;
> - char *secctx;
> + int ret;
> struct lsmblob blob;
> struct lsmcontext context;
>
> lsmblob_init(&blob, ct->secmark);
> - ret = security_secid_to_secctx(&blob, &secctx, &len);
> + ret = security_secid_to_secctx(&blob, &context);
> if (ret)
> return 0;
>
> @@ -343,13 +342,12 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
> if (!nest_secctx)
> goto nla_put_failure;
>
> - if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
> + if (nla_put_string(skb, CTA_SECCTX_NAME, context.context))
> goto nla_put_failure;
> nla_nest_end(skb, nest_secctx);
>
> ret = 0;
> nla_put_failure:
> - lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> security_release_secctx(&context);
> return ret;
> }
> @@ -620,12 +618,16 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
> #ifdef CONFIG_NF_CONNTRACK_SECMARK
> int len, ret;
> struct lsmblob blob;
> + struct lsmcontext context;
>
> lsmblob_init(&blob, ct->secmark);
> - ret = security_secid_to_secctx(&blob, NULL, &len);
> + ret = security_secid_to_secctx(&blob, &context);
> if (ret)
> return 0;
>
> + len = context.len;
> + security_release_secctx(&context);
> +
> return nla_total_size(0) /* CTA_SECCTX */
> + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
> #else
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index 79158ad0486e..fcb51ab2bb8b 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -173,19 +173,16 @@ static void ct_seq_stop(struct seq_file *s, void *v)
> static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
> {
> int ret;
> - u32 len;
> - char *secctx;
> struct lsmblob blob;
> struct lsmcontext context;
>
> lsmblob_init(&blob, ct->secmark);
> - ret = security_secid_to_secctx(&blob, &secctx, &len);
> + ret = security_secid_to_secctx(&blob, &context);
> if (ret)
> return;
>
> - seq_printf(s, "secctx=%s ", secctx);
> + seq_printf(s, "secctx=%s ", context.context);
>
> - lsmcontext_init(&context, secctx, len, 0); /* scaffolding */
> security_release_secctx(&context);
> }
> #else
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index fe8403ef4e89..6da00c7add5b 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -310,6 +310,7 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> u32 seclen = 0;
> #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
> struct lsmblob blob;
> + struct lsmcontext context;
>
> if (!skb || !sk_fullsock(skb->sk))
> return 0;
> @@ -318,10 +319,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
>
> if (skb->secmark) {
> lsmblob_init(&blob, skb->secmark);
> - security_secid_to_secctx(&blob, secdata, &seclen);
> + security_secid_to_secctx(&blob, &context);
> + *secdata = context.context;
> }
>
> read_unlock_bh(&skb->sk->sk_callback_lock);
> + seclen = context.len;
> #endif
> return seclen;
> }
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 15b1945853be..4716e0011ba5 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -388,8 +388,6 @@ int netlbl_unlhsh_add(struct net *net,
> struct netlbl_unlhsh_iface *iface;
> struct audit_buffer *audit_buf = NULL;
> struct lsmcontext context;
> - char *secctx = NULL;
> - u32 secctx_len;
> struct lsmblob blob;
>
> if (addr_len != sizeof(struct in_addr) &&
> @@ -454,12 +452,9 @@ int netlbl_unlhsh_add(struct net *net,
> rcu_read_unlock();
> if (audit_buf != NULL) {
> lsmblob_init(&blob, secid);
> - if (security_secid_to_secctx(&blob,
> - &secctx,
> - &secctx_len) == 0) {
> - audit_log_format(audit_buf, " sec_obj=%s", secctx);
> - /* scaffolding */
> - lsmcontext_init(&context, secctx, secctx_len, 0);
> + if (security_secid_to_secctx(&blob, &context) == 0) {
> + audit_log_format(audit_buf, " sec_obj=%s",
> + context.context);
> security_release_secctx(&context);
> }
> audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
> @@ -492,8 +487,6 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
> struct audit_buffer *audit_buf;
> struct net_device *dev;
> struct lsmcontext context;
> - char *secctx;
> - u32 secctx_len;
> struct lsmblob blob;
>
> spin_lock(&netlbl_unlhsh_lock);
> @@ -517,11 +510,9 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
> if (entry != NULL)
> lsmblob_init(&blob, entry->secid);
> if (entry != NULL &&
> - security_secid_to_secctx(&blob,
> - &secctx, &secctx_len) == 0) {
> - audit_log_format(audit_buf, " sec_obj=%s", secctx);
> - /* scaffolding */
> - lsmcontext_init(&context, secctx, secctx_len, 0);
> + security_secid_to_secctx(&blob, &context) == 0) {
> + audit_log_format(audit_buf, " sec_obj=%s",
> + context.context);
> security_release_secctx(&context);
> }
> audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -560,8 +551,6 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
> struct audit_buffer *audit_buf;
> struct net_device *dev;
> struct lsmcontext context;
> - char *secctx;
> - u32 secctx_len;
> struct lsmblob blob;
>
> spin_lock(&netlbl_unlhsh_lock);
> @@ -584,10 +573,9 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
> if (entry != NULL)
> lsmblob_init(&blob, entry->secid);
> if (entry != NULL &&
> - security_secid_to_secctx(&blob,
> - &secctx, &secctx_len) == 0) {
> - audit_log_format(audit_buf, " sec_obj=%s", secctx);
> - lsmcontext_init(&context, secctx, secctx_len, 0);
> + security_secid_to_secctx(&blob, &context) == 0) {
> + audit_log_format(audit_buf, " sec_obj=%s",
> + context.context);
> security_release_secctx(&context);
> }
> audit_log_format(audit_buf, " res=%u", entry != NULL ? 1 : 0);
> @@ -1105,8 +1093,6 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
> struct lsmcontext context;
> void *data;
> u32 secid;
> - char *secctx;
> - u32 secctx_len;
> struct lsmblob blob;
>
> data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
> @@ -1163,15 +1149,13 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
> }
>
> lsmblob_init(&blob, secid);
> - ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
> + ret_val = security_secid_to_secctx(&blob, &context);
> if (ret_val != 0)
> goto list_cb_failure;
> ret_val = nla_put(cb_arg->skb,
> NLBL_UNLABEL_A_SECCTX,
> - secctx_len,
> - secctx);
> - /* scaffolding */
> - lsmcontext_init(&context, secctx, secctx_len, 0);
> + context.len,
> + context.context);
> security_release_secctx(&context);
> if (ret_val != 0)
> goto list_cb_failure;
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 94aea4985b74..2d1307f65250 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -99,8 +99,6 @@ struct audit_buffer *netlbl_audit_start_common(int type,
> {
> struct audit_buffer *audit_buf;
> struct lsmcontext context;
> - char *secctx;
> - u32 secctx_len;
> struct lsmblob blob;
>
> if (audit_enabled == AUDIT_OFF)
> @@ -116,9 +114,8 @@ struct audit_buffer *netlbl_audit_start_common(int type,
>
> lsmblob_init(&blob, audit_info->secid);
> if (audit_info->secid != 0 &&
> - security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
> - audit_log_format(audit_buf, " subj=%s", secctx);
> - lsmcontext_init(&context, secctx, secctx_len, 0);/*scaffolding*/
> + security_secid_to_secctx(&blob, &context) == 0) {
> + audit_log_format(audit_buf, " subj=%s", context.context);
> security_release_secctx(&context);
> }
>
> diff --git a/security/security.c b/security/security.c
> index 3563b1e2f8f9..97b468f6e6a9 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2081,7 +2081,7 @@ int security_ismaclabel(const char *name)
> }
> EXPORT_SYMBOL(security_ismaclabel);
>
> -int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, struct lsmcontext *cp)
> {
> struct security_hook_list *hp;
> int *display = current->security;
> @@ -2089,10 +2089,13 @@ int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> continue;
> - if (*display == LSMBLOB_INVALID || *display == hp->lsmid->slot)
> + if (*display == LSMBLOB_INVALID ||
> + *display == hp->lsmid->slot) {
> + cp->slot = hp->lsmid->slot;
> return hp->hook.secid_to_secctx(
> blob->secid[hp->lsmid->slot],
> - secdata, seclen);
> + &cp->context, &cp->len);
> + }
> }
> return 0;
> }
> --
> 2.20.1
>
--
Kees Cook
^ permalink raw reply
* Re: [PATCH v4 00/23] LSM: Module stacking for AppArmor
From: Kees Cook @ 2019-06-27 3:51 UTC (permalink / raw)
To: James Morris
Cc: Casey Schaufler, casey.schaufler, linux-security-module, selinux,
John Johansen, Tetsuo Handa, Paul Moore, Stephen Smalley
In-Reply-To: <alpine.LRH.2.21.1906271245210.13254@namei.org>
On Thu, Jun 27, 2019 at 12:46:01PM +1000, James Morris wrote:
> On Thu, 27 Jun 2019, James Morris wrote:
>
> > On Wed, 26 Jun 2019, Casey Schaufler wrote:
> >
> > > This patchset provides the changes required for
> > > the AppArmor security module to stack safely with any other.
> >
> > I get a kernel oops with this patchset when running the SELinux testsuite
> > (binder test) with:
> >
> > $ cat /sys/kernel/security/lsm
> > capability,yama,loadpin,safesetid,selinux,tomoyo
> >
> >
> > [ 485.357377] binder: 4224 RLIMIT_NICE not set
> > [ 485.360727] binder: 4224 RLIMIT_NICE not set
> > [ 485.361480] binder: 4224 RLIMIT_NICE not set
> > [ 485.362164] BUG: unable to handle kernel paging request at 0000000000001080
> > [ 485.362927] #PF error: [normal kernel read fault]
> > [ 485.363143] ------------[ cut here ]------------
> > [ 485.363581] PGD 800000044e17b067 P4D 800000044e17b067 PUD 44b796067 PMD 0
> > [ 485.364226] kernel BUG at drivers/android/binder_alloc.c:1139!
>
> It's this BUG_ON:
>
> static void binder_alloc_do_buffer_copy(struct binder_alloc *alloc,
> bool to_buffer,
> struct binder_buffer *buffer,
> binder_size_t buffer_offset,
> void *ptr,
> size_t bytes)
> {
> /* All copies must be 32-bit aligned and 32-bit size */
> BUG_ON(!check_buffer(alloc, buffer, buffer_offset, bytes));
Before:
if (secctx) {
size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
ALIGN(tr->offsets_size, sizeof(void *)) +
ALIGN(extra_buffers_size, sizeof(void *)) -
ALIGN(secctx_sz, sizeof(u64));
t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
secctx, secctx_sz);
security_release_secctx(secctx, secctx_sz);
secctx = NULL;
}
After:
if (lsmctx.context) {
size_t buf_offset = ALIGN(tr->data_size, sizeof(void *)) +
ALIGN(tr->offsets_size, sizeof(void *)) +
ALIGN(extra_buffers_size, sizeof(void *)) -
ALIGN(lsmctx.len, sizeof(u64));
t->security_ctx = (uintptr_t)t->buffer->user_data + buf_offset;
binder_alloc_copy_to_buffer(&target_proc->alloc,
t->buffer, buf_offset,
lsmctx.context, lsmctx.len);
security_release_secctx(&lsmctx);
}
Which changes the "src" and "bytes" argument, assuming the size
calculation for buf_offset is the same. But, a quick shows:
- char *secctx = NULL;
- u32 secctx_sz = 0;
+ struct lsmcontext lsmctx;
...
- if (secctx) {
+ if (lsmctx.context) {
lsmctx.context isn't being initialized, and it was passed by reference,
so compiler won't complain. I'll find the patch and comment. Totally
missed it in review!
--
Kees Cook
^ permalink raw reply
* Re: [PATCH v4 23/23] AppArmor: Remove the exclusive flag
From: James Morris @ 2019-06-27 3:49 UTC (permalink / raw)
To: John Johansen
Cc: Casey Schaufler, casey.schaufler, linux-security-module, selinux,
keescook, penguin-kernel, paul, sds
In-Reply-To: <d89fbbe9-49cb-646e-6cba-7951cf835bf9@canonical.com>
On Wed, 26 Jun 2019, John Johansen wrote:
> AppArmor can be built-in (compiled) without being on the Enabled list.
> If you had apparmor in your enabled list along with selinux before,
> it would attempt to enabled and fail with the message
>
> exclusive disabled: apparmor
>
> now it will be enabled but it does match what is documented in
> the lsm enabled description
>
> A comma-separated list of LSMs, in initialization order.
> Any LSMs left off this list will be ignored. This can be
> controlled at boot with the "lsm=" parameter.
Ok -- I suspect the only people who have SELinux and AppArmor selected are
doing testing / development.
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH v4 00/23] LSM: Module stacking for AppArmor
From: James Morris @ 2019-06-27 3:45 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, Kees Cook,
John Johansen, Tetsuo Handa, Paul Moore, Stephen Smalley
In-Reply-To: <alpine.LRH.2.21.1906271245210.13254@namei.org>
On Thu, 27 Jun 2019, James Morris wrote:
> On Thu, 27 Jun 2019, James Morris wrote:
>
> > On Wed, 26 Jun 2019, Casey Schaufler wrote:
> >
> > > This patchset provides the changes required for
> > > the AppArmor security module to stack safely with any other.
> >
> > I get a kernel oops with this patchset when running the SELinux testsuite
> > (binder test) with:
> >
> > $ cat /sys/kernel/security/lsm
> > capability,yama,loadpin,safesetid,selinux,tomoyo
Confirming there's no oops when Tomoyo is un-selected in the kernel
config.
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH v4 23/23] AppArmor: Remove the exclusive flag
From: John Johansen @ 2019-06-27 3:44 UTC (permalink / raw)
To: James Morris, Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, keescook,
penguin-kernel, paul, sds
In-Reply-To: <alpine.LRH.2.21.1906271219450.12379@namei.org>
On 6/26/19 7:22 PM, James Morris wrote:
> On Wed, 26 Jun 2019, Casey Schaufler wrote:
>
>> With the inclusion of the "display" process attribute
>> mechanism AppArmor no longer needs to be treated as an
>> "exclusive" security module. Remove the flag that indicates
>> it is exclusive. Remove the stub getpeersec_dgram AppArmor
>> hook as it has no effect in the single LSM case and
>> interferes in the multiple LSM case.
>
> So now if I build a kernel with SELinux and AppArmor selected, with
> SELinux registered first, I now need to use apparmor=0 at the kernel
> command line to preserve existing behavior (just SELinux running).
>
AppArmor can be built-in (compiled) without being on the Enabled list.
If you had apparmor in your enabled list along with selinux before,
it would attempt to enabled and fail with the message
exclusive disabled: apparmor
now it will be enabled but it does match what is documented in
the lsm enabled description
A comma-separated list of LSMs, in initialization order.
Any LSMs left off this list will be ignored. This can be
controlled at boot with the "lsm=" parameter.
what isn't documented is the exclusive behavior and it does
make sense to have which LSMs are exclusive documented somewhere.
> This should at least be documented.
>
> I wonder if this will break existing users, though. Who has both
> currently selected and depends on only one of them being active?
>
thankfully even if you had apparmor in your lsm enabled list before,
this likely isn't enough to change the system behavior. You will
also need some apparmor policy installed and enough of the
usersoace to load it. Otherwise while apparmor will be enabled it
will come up in unconfined mode.
Even the interfaces /proc/*/attr/* will default to the first
major LSM in the list (in your example selinux). Apparmor's
labeling won't be visible without a task explicitly opting in
to it.
^ permalink raw reply
* Re: [PATCH v4 23/23] AppArmor: Remove the exclusive flag
From: Kees Cook @ 2019-06-27 3:28 UTC (permalink / raw)
To: James Morris
Cc: Casey Schaufler, casey.schaufler, linux-security-module, selinux,
john.johansen, penguin-kernel, paul, sds
In-Reply-To: <alpine.LRH.2.21.1906271219450.12379@namei.org>
On Thu, Jun 27, 2019 at 12:22:13PM +1000, James Morris wrote:
> On Wed, 26 Jun 2019, Casey Schaufler wrote:
>
> > With the inclusion of the "display" process attribute
> > mechanism AppArmor no longer needs to be treated as an
> > "exclusive" security module. Remove the flag that indicates
> > it is exclusive. Remove the stub getpeersec_dgram AppArmor
> > hook as it has no effect in the single LSM case and
> > interferes in the multiple LSM case.
>
> So now if I build a kernel with SELinux and AppArmor selected, with
> SELinux registered first, I now need to use apparmor=0 at the kernel
> command line to preserve existing behavior (just SELinux running).
>
> This should at least be documented.
>
> I wonder if this will break existing users, though. Who has both
> currently selected and depends on only one of them being active?
I don't think this will change a system using SELinux, right? There
would be no policy loaded for AppArmor so its hooks would be no-op.
But maybe I'm not thinking hard enough?
--
Kees Cook
^ permalink raw reply
* Re: [PATCH v4 00/23] LSM: Module stacking for AppArmor
From: James Morris @ 2019-06-27 2:46 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, Kees Cook,
John Johansen, Tetsuo Handa, Paul Moore, Stephen Smalley
In-Reply-To: <alpine.LRH.2.21.1906271230490.12379@namei.org>
On Thu, 27 Jun 2019, James Morris wrote:
> On Wed, 26 Jun 2019, Casey Schaufler wrote:
>
> > This patchset provides the changes required for
> > the AppArmor security module to stack safely with any other.
>
> I get a kernel oops with this patchset when running the SELinux testsuite
> (binder test) with:
>
> $ cat /sys/kernel/security/lsm
> capability,yama,loadpin,safesetid,selinux,tomoyo
>
>
> [ 485.357377] binder: 4224 RLIMIT_NICE not set
> [ 485.360727] binder: 4224 RLIMIT_NICE not set
> [ 485.361480] binder: 4224 RLIMIT_NICE not set
> [ 485.362164] BUG: unable to handle kernel paging request at 0000000000001080
> [ 485.362927] #PF error: [normal kernel read fault]
> [ 485.363143] ------------[ cut here ]------------
> [ 485.363581] PGD 800000044e17b067 P4D 800000044e17b067 PUD 44b796067 PMD 0
> [ 485.364226] kernel BUG at drivers/android/binder_alloc.c:1139!
It's this BUG_ON:
static void binder_alloc_do_buffer_copy(struct binder_alloc *alloc,
bool to_buffer,
struct binder_buffer *buffer,
binder_size_t buffer_offset,
void *ptr,
size_t bytes)
{
/* All copies must be 32-bit aligned and 32-bit size */
BUG_ON(!check_buffer(alloc, buffer, buffer_offset, bytes));
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH v4 00/23] LSM: Module stacking for AppArmor
From: James Morris @ 2019-06-27 2:41 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, Kees Cook,
John Johansen, Tetsuo Handa, Paul Moore, Stephen Smalley
In-Reply-To: <20190626192234.11725-1-casey@schaufler-ca.com>
On Wed, 26 Jun 2019, Casey Schaufler wrote:
> This patchset provides the changes required for
> the AppArmor security module to stack safely with any other.
I get a kernel oops with this patchset when running the SELinux testsuite
(binder test) with:
$ cat /sys/kernel/security/lsm
capability,yama,loadpin,safesetid,selinux,tomoyo
[ 485.357377] binder: 4224 RLIMIT_NICE not set
[ 485.360727] binder: 4224 RLIMIT_NICE not set
[ 485.361480] binder: 4224 RLIMIT_NICE not set
[ 485.362164] BUG: unable to handle kernel paging request at 0000000000001080
[ 485.362927] #PF error: [normal kernel read fault]
[ 485.363143] ------------[ cut here ]------------
[ 485.363581] PGD 800000044e17b067 P4D 800000044e17b067 PUD 44b796067 PMD 0
[ 485.364226] kernel BUG at drivers/android/binder_alloc.c:1139!
[ 485.364865] Oops: 0000 [#1] SMP PTI
[ 485.366430] CPU: 1 PID: 4224 Comm: manager Not tainted 5.1.0+ #7
[ 485.367290] Hardware name: LENOVO 20HGS3KS0S/20HGS3KS0S, BIOS N1WET44W (1.23 ) 01/24/2018
[ 485.367900] RIP: 0010:binder_alloc_do_buffer_copy+0x88/0x210
[ 485.368515] Code: 00 65 48 8b 2c 25 00 5c 01 00 41 bd 00 10 00 00 48 89
eb eb 3d 83 f8 08 0f 83 e3 00 00 00 a8 04 0f
85 45 01 00 00 85 c0 74 0e <41> 0f b6 08 88 0e a8 02 0f 85 5d 01 00 00 83
ab a8 19 00 00 01 49
[ 485.369170] RSP: 0018:ffffaf3ac1f9bb88 EFLAGS: 00010202
[ 485.369804] RAX: 0000000000000002 RBX: ffff8d3c84340000 RCX: 0000000000000000
[ 485.370470] RDX: ffff8d3c8db74cc0 RSI: ffff8d3c8b425000 RDI: ffff8d3c89844978
[ 485.371132] RBP: ffff8d3c84340000 R08: 0000000000001080 R09: 0000000000000002
[ 485.371887] R10: 0000000000000000 R11: ffff8d3c89844978 R12: 0000000000000001
[ 485.372656] R13: 0000000000001000 R14: ffff8d3c865d6300 R15: ffffffffa1a719c8
[ 485.373340] FS: 00007fae657a8680(0000) GS:ffff8d3c91480000(0000) knlGS:0000000000000000
[ 485.374017] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 485.374710] CR2: 0000000000001080 CR3: 000000044d482002 CR4: 00000000003606e0
[ 485.375423] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 485.376122] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 485.376823] Call Trace:
[ 485.377514] binder_transaction+0x371/0x2320
[ 485.378231] ? printk+0x58/0x6f
[ 485.378940] ? common_lsm_audit+0x162/0x800
[ 485.379641] ? __check_object_size+0x41/0x15d
[ 485.380347] ? binder_thread_read+0x9e4/0x1460
[ 485.381065] ? binder_update_ref_for_handle+0x83/0x1a0
[ 485.381759] binder_thread_write+0x2ae/0xfc0
[ 485.382472] ? tomoyo_path_number_perm+0x66/0x1d0
[ 485.383150] ? finish_wait+0x80/0x80
[ 485.383839] binder_ioctl+0x659/0x836
[ 485.384531] do_vfs_ioctl+0x405/0x660
[ 485.385194] ? __fput+0x157/0x230
[ 485.385850] ksys_ioctl+0x5e/0x90
[ 485.386473] __x64_sys_ioctl+0x16/0x20
[ 485.387137] do_syscall_64+0x5b/0x150
[ 485.387782] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Looks to be:
(gdb) list *(binder_alloc_do_buffer_copy + 0x88)
0xffffffff817e2cb8 is in binder_alloc_do_buffer_copy
(./include/linux/string.h:355).
350 if (q_size < size)
351 __read_overflow2();
352 }
353 if (p_size < size || q_size < size)
354 fortify_panic(__func__);
355 return __builtin_memcpy(p, q, size);
356 }
357
^ permalink raw reply
* Re: [PATCH v4 23/23] AppArmor: Remove the exclusive flag
From: James Morris @ 2019-06-27 2:22 UTC (permalink / raw)
To: Casey Schaufler
Cc: casey.schaufler, linux-security-module, selinux, keescook,
john.johansen, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-24-casey@schaufler-ca.com>
On Wed, 26 Jun 2019, Casey Schaufler wrote:
> With the inclusion of the "display" process attribute
> mechanism AppArmor no longer needs to be treated as an
> "exclusive" security module. Remove the flag that indicates
> it is exclusive. Remove the stub getpeersec_dgram AppArmor
> hook as it has no effect in the single LSM case and
> interferes in the multiple LSM case.
So now if I build a kernel with SELinux and AppArmor selected, with
SELinux registered first, I now need to use apparmor=0 at the kernel
command line to preserve existing behavior (just SELinux running).
This should at least be documented.
I wonder if this will break existing users, though. Who has both
currently selected and depends on only one of them being active?
--
James Morris
<jmorris@namei.org>
^ permalink raw reply
* Re: [PATCH V34 19/29] Lock down module params that specify hardware parameters (eg. ioport)
From: Daniel Axtens @ 2019-06-27 1:49 UTC (permalink / raw)
To: Matthew Garrett, jmorris
Cc: linux-security-module, linux-kernel, linux-api, David Howells,
Alan Cox, Matthew Garrett
In-Reply-To: <20190622000358.19895-20-matthewgarrett@google.com>
Matthew Garrett <matthewgarrett@google.com> writes:
> From: David Howells <dhowells@redhat.com>
>
> Provided an annotation for module parameters that specify hardware
> parameters (such as io ports, iomem addresses, irqs, dma channels, fixed
> dma buffers and other types).
>
> Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Matthew Garrett <mjg59@google.com>
> ---
> include/linux/security.h | 1 +
> kernel/params.c | 27 ++++++++++++++++++++++-----
> security/lockdown/lockdown.c | 1 +
> 3 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 61e3f4a62d16..88064d7f6827 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -92,6 +92,7 @@ enum lockdown_reason {
> LOCKDOWN_ACPI_TABLES,
> LOCKDOWN_PCMCIA_CIS,
> LOCKDOWN_TIOCSSERIAL,
> + LOCKDOWN_MODULE_PARAMETERS,
> LOCKDOWN_INTEGRITY_MAX,
> LOCKDOWN_CONFIDENTIALITY_MAX,
> };
> diff --git a/kernel/params.c b/kernel/params.c
> index ce89f757e6da..f94fe79e331d 100644
> --- a/kernel/params.c
> +++ b/kernel/params.c
> @@ -24,6 +24,7 @@
> #include <linux/err.h>
> #include <linux/slab.h>
> #include <linux/ctype.h>
> +#include <linux/security.h>
>
> #ifdef CONFIG_SYSFS
> /* Protects all built-in parameters, modules use their own param_lock */
> @@ -108,13 +109,19 @@ bool parameq(const char *a, const char *b)
> return parameqn(a, b, strlen(a)+1);
> }
>
> -static void param_check_unsafe(const struct kernel_param *kp)
> +static bool param_check_unsafe(const struct kernel_param *kp,
> + const char *doing)
> {
> if (kp->flags & KERNEL_PARAM_FL_UNSAFE) {
> pr_notice("Setting dangerous option %s - tainting kernel\n",
> kp->name);
> add_taint(TAINT_USER, LOCKDEP_STILL_OK);
> }
> +
> + if (kp->flags & KERNEL_PARAM_FL_HWPARAM &&
> + security_locked_down(LOCKDOWN_MODULE_PARAMETERS))
> + return false;
> + return true;
> }
Should this test occur before tainting the kernel?
Regards,
Daniel
>
> static int parse_one(char *param,
> @@ -144,8 +151,10 @@ static int parse_one(char *param,
> pr_debug("handling %s with %p\n", param,
> params[i].ops->set);
> kernel_param_lock(params[i].mod);
> - param_check_unsafe(¶ms[i]);
> - err = params[i].ops->set(val, ¶ms[i]);
> + if (param_check_unsafe(¶ms[i], doing))
> + err = params[i].ops->set(val, ¶ms[i]);
> + else
> + err = -EPERM;
> kernel_param_unlock(params[i].mod);
> return err;
> }
> @@ -553,6 +562,12 @@ static ssize_t param_attr_show(struct module_attribute *mattr,
> return count;
> }
>
> +#ifdef CONFIG_MODULES
> +#define mod_name(mod) (mod)->name
> +#else
> +#define mod_name(mod) "unknown"
> +#endif
> +
> /* sysfs always hands a nul-terminated string in buf. We rely on that. */
> static ssize_t param_attr_store(struct module_attribute *mattr,
> struct module_kobject *mk,
> @@ -565,8 +580,10 @@ static ssize_t param_attr_store(struct module_attribute *mattr,
> return -EPERM;
>
> kernel_param_lock(mk->mod);
> - param_check_unsafe(attribute->param);
> - err = attribute->param->ops->set(buf, attribute->param);
> + if (param_check_unsafe(attribute->param, mod_name(mk->mod)))
> + err = attribute->param->ops->set(buf, attribute->param);
> + else
> + err = -EPERM;
> kernel_param_unlock(mk->mod);
> if (!err)
> return len;
> diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c
> index c89046dc2155..d03c4c296af7 100644
> --- a/security/lockdown/lockdown.c
> +++ b/security/lockdown/lockdown.c
> @@ -28,6 +28,7 @@ static char *lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
> [LOCKDOWN_ACPI_TABLES] = "modified ACPI tables",
> [LOCKDOWN_PCMCIA_CIS] = "direct PCMCIA CIS storage",
> [LOCKDOWN_TIOCSSERIAL] = "reconfiguration of serial port IO",
> + [LOCKDOWN_MODULE_PARAMETERS] = "unsafe module parameters",
> [LOCKDOWN_INTEGRITY_MAX] = "integrity",
> [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
> };
> --
> 2.22.0.410.gd8fdbe21b5-goog
^ permalink raw reply
* Re: [PATCH V33 24/30] bpf: Restrict bpf when kernel lockdown is in confidentiality mode
From: Andy Lutomirski @ 2019-06-27 0:57 UTC (permalink / raw)
To: James Morris
Cc: Andy Lutomirski, Matthew Garrett, linux-security, LKML, Linux API,
David Howells, Alexei Starovoitov, Matthew Garrett,
Network Development, Chun-Yi Lee, Daniel Borkmann,
linux-security-module
In-Reply-To: <alpine.LRH.2.21.1906270621080.28132@namei.org>
> On Jun 26, 2019, at 1:22 PM, James Morris <jmorris@namei.org> wrote:
>
> [Adding the LSM mailing list: missed this patchset initially]
>
>> On Thu, 20 Jun 2019, Andy Lutomirski wrote:
>>
>> This patch exemplifies why I don't like this approach:
>>
>>> @@ -97,6 +97,7 @@ enum lockdown_reason {
>>> LOCKDOWN_INTEGRITY_MAX,
>>> LOCKDOWN_KCORE,
>>> LOCKDOWN_KPROBES,
>>> + LOCKDOWN_BPF,
>>> LOCKDOWN_CONFIDENTIALITY_MAX,
>>
>>> --- a/security/lockdown/lockdown.c
>>> +++ b/security/lockdown/lockdown.c
>>> @@ -33,6 +33,7 @@ static char *lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX+1] = {
>>> [LOCKDOWN_INTEGRITY_MAX] = "integrity",
>>> [LOCKDOWN_KCORE] = "/proc/kcore access",
>>> [LOCKDOWN_KPROBES] = "use of kprobes",
>>> + [LOCKDOWN_BPF] = "use of bpf",
>>> [LOCKDOWN_CONFIDENTIALITY_MAX] = "confidentiality",
>>
>> The text here says "use of bpf", but what this patch is *really* doing
>> is locking down use of BPF to read kernel memory. If the details
>> change, then every LSM needs to get updated, and we risk breaking user
>> policies that are based on LSMs that offer excessively fine
>> granularity.
>
> Can you give an example of how the details might change?
>
>> I'd be more comfortable if the LSM only got to see "confidentiality"
>> or "integrity".
>
> These are not sufficient for creating a useful policy for the SELinux
> case.
>
>
I may have misunderstood, but I thought that SELinux mainly needed to allow certain privileged programs to bypass the policy. Is there a real example of what SELinux wants to do that can’t be done in the simplified model?
The think that specifically makes me uneasy about exposing all of these precise actions to LSMs is that they will get exposed to userspace in a way that forces us to treat them as stable ABIs.
^ permalink raw reply
* Re: [PATCH v4 14/23] IMA: Change internal interfaces to use lsmblobs
From: John Johansen @ 2019-06-26 23:58 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-15-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> The IMA interfaces ima_get_action() and ima_match_policy()
> call LSM functions that use lsmblobs. Change the IMA functions
> to pass the lsmblob to be compatible with the LSM functions.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> security/integrity/ima/ima.h | 10 ++++++----
> security/integrity/ima/ima_api.c | 9 +++++----
> security/integrity/ima/ima_appraise.c | 4 +---
> security/integrity/ima/ima_main.c | 27 +++++++++++----------------
> security/integrity/ima/ima_policy.c | 12 ++++++------
> 5 files changed, 29 insertions(+), 33 deletions(-)
>
> diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
> index 5a337239d9e4..73b3b15dec5c 100644
> --- a/security/integrity/ima/ima.h
> +++ b/security/integrity/ima/ima.h
> @@ -192,8 +192,9 @@ enum ima_hooks {
> };
>
> /* LIM API function definitions */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> - int mask, enum ima_hooks func, int *pcr);
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, int mask, enum ima_hooks func,
> + int *pcr);
> int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
> int ima_collect_measurement(struct integrity_iint_cache *iint,
> struct file *file, void *buf, loff_t size,
> @@ -213,8 +214,9 @@ void ima_free_template_entry(struct ima_template_entry *entry);
> const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
>
> /* IMA policy related functions */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> - enum ima_hooks func, int mask, int flags, int *pcr);
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, enum ima_hooks func, int mask,
> + int flags, int *pcr);
> void ima_init_policy(void);
> void ima_update_policy(void);
> void ima_update_policy_flag(void);
> diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
> index c7505fb122d4..94b2a4840d81 100644
> --- a/security/integrity/ima/ima_api.c
> +++ b/security/integrity/ima/ima_api.c
> @@ -159,7 +159,7 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
> * ima_get_action - appraise & measure decision based on policy.
> * @inode: pointer to inode to measure
> * @cred: pointer to credentials structure to validate
> - * @secid: secid of the task being validated
> + * @blob: LSM data of the task being validated
> * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXEC,
> * MAY_APPEND)
> * @func: caller identifier
> @@ -175,14 +175,15 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
> * Returns IMA_MEASURE, IMA_APPRAISE mask.
> *
> */
> -int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
> - int mask, enum ima_hooks func, int *pcr)
> +int ima_get_action(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, int mask, enum ima_hooks func,
> + int *pcr)
> {
> int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
>
> flags &= ima_policy_flag;
>
> - return ima_match_policy(inode, cred, secid, func, mask, flags, pcr);
> + return ima_match_policy(inode, cred, blob, func, mask, flags, pcr);
> }
>
> /*
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 85c7692fc4a3..3ff7aae81829 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -50,15 +50,13 @@ bool is_ima_appraise_enabled(void)
> */
> int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
> {
> - u32 secid;
> struct lsmblob blob;
>
> if (!ima_appraise)
> return 0;
>
> security_task_getsecid(current, &blob);
> - lsmblob_secid(&blob, &secid);
> - return ima_match_policy(inode, current_cred(), secid, func, mask,
> + return ima_match_policy(inode, current_cred(), &blob, func, mask,
> IMA_APPRAISE | IMA_HASH, NULL);
> }
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 1afb75a893af..0588dd9a88db 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -169,8 +169,8 @@ void ima_file_free(struct file *file)
> }
>
> static int process_measurement(struct file *file, const struct cred *cred,
> - u32 secid, char *buf, loff_t size, int mask,
> - enum ima_hooks func)
> + struct lsmblob *blob, char *buf, loff_t size,
> + int mask, enum ima_hooks func)
> {
> struct inode *inode = file_inode(file);
> struct integrity_iint_cache *iint = NULL;
> @@ -192,7 +192,7 @@ static int process_measurement(struct file *file, const struct cred *cred,
> * bitmask based on the appraise/audit/measurement policy.
> * Included is the appraise submask.
> */
> - action = ima_get_action(inode, cred, secid, mask, func, &pcr);
> + action = ima_get_action(inode, cred, blob, mask, func, &pcr);
> violation_check = ((func == FILE_CHECK || func == MMAP_CHECK) &&
> (ima_policy_flag & IMA_MEASURE));
> if (!action && !violation_check)
> @@ -339,8 +339,7 @@ int ima_file_mmap(struct file *file, unsigned long prot)
>
> if (file && (prot & PROT_EXEC)) {
> security_task_getsecid(current, &blob);
> - /* scaffolding - until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0],
> + return process_measurement(file, current_cred(), &blob,
> NULL, 0, MAY_EXEC, MMAP_CHECK);
> }
>
> @@ -366,16 +365,14 @@ int ima_bprm_check(struct linux_binprm *bprm)
> struct lsmblob blob;
>
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> - NULL, 0, MAY_EXEC, BPRM_CHECK);
> + ret = process_measurement(bprm->file, current_cred(), &blob, NULL, 0,
> + MAY_EXEC, BPRM_CHECK);
> if (ret)
> return ret;
>
> security_cred_getsecid(bprm->cred, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> - NULL, 0, MAY_EXEC, CREDS_CHECK);
> + return process_measurement(bprm->file, bprm->cred, &blob, NULL, 0,
> + MAY_EXEC, CREDS_CHECK);
> }
>
> /**
> @@ -393,8 +390,7 @@ int ima_file_check(struct file *file, int mask)
> struct lsmblob blob;
>
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
> + return process_measurement(file, current_cred(), &blob, NULL, 0,
> mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
> MAY_APPEND), FILE_CHECK);
> }
> @@ -526,9 +522,8 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
>
> func = read_idmap[read_id] ?: FILE_CHECK;
> security_task_getsecid(current, &blob);
> - /* scaffolding until process_measurement changes */
> - return process_measurement(file, current_cred(), blob.secid[0], buf,
> - size, MAY_READ, func);
> + return process_measurement(file, current_cred(), &blob, buf, size,
> + MAY_READ, func);
> }
>
> /**
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 92ee3d984c73..dbad256aa7b4 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -286,7 +286,7 @@ static void ima_lsm_update_rules(void)
> * Returns true on rule match, false on failure.
> */
> static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> - const struct cred *cred, u32 secid,
> + const struct cred *cred, struct lsmblob *blob,
> enum ima_hooks func, int mask)
> {
> int i;
> @@ -345,7 +345,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> case LSM_SUBJ_USER:
> case LSM_SUBJ_ROLE:
> case LSM_SUBJ_TYPE:
> - lsmblob_init(&blob, secid);
> rc = security_filter_rule_match(&blob,
> rule->lsm[i].type,
> Audit_equal,
> @@ -394,7 +393,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
> * @inode: pointer to an inode for which the policy decision is being made
> * @cred: pointer to a credentials structure for which the policy decision is
> * being made
> - * @secid: LSM secid of the task to be validated
> + * @blob: LSM data of the task to be validated
> * @func: IMA hook identifier
> * @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
> * @pcr: set the pcr to extend
> @@ -406,8 +405,9 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
> * list when walking it. Reads are many orders of magnitude more numerous
> * than writes so ima_match_policy() is classical RCU candidate.
> */
> -int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> - enum ima_hooks func, int mask, int flags, int *pcr)
> +int ima_match_policy(struct inode *inode, const struct cred *cred,
> + struct lsmblob *blob, enum ima_hooks func, int mask,
> + int flags, int *pcr)
> {
> struct ima_rule_entry *entry;
> int action = 0, actmask = flags | (flags << 1);
> @@ -418,7 +418,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
> if (!(entry->action & actmask))
> continue;
>
> - if (!ima_match_rules(entry, inode, cred, secid, func, mask))
> + if (!ima_match_rules(entry, inode, cred, blob, func, mask))
> continue;
>
> action |= entry->flags & IMA_ACTION_FLAGS;
>
^ permalink raw reply
* Re: [PATCH v4 13/23] LSM: Use lsmblob in security_cred_getsecid
From: John Johansen @ 2019-06-26 23:57 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-14-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change the security_cred_getsecid() interface to fill in a
> lsmblob instead of a u32 secid. The associated data elements
> in the audit sub-system are changed from a secid to a lsmblob
> to accomodate multiple possible LSM audit users.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> include/linux/security.h | 2 +-
> kernel/audit.c | 14 +++++-------
> kernel/audit.h | 5 +++--
> kernel/auditsc.c | 37 +++++++++++--------------------
> security/integrity/ima/ima_main.c | 8 +++----
> security/security.c | 12 +++++++---
> 6 files changed, 36 insertions(+), 42 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 2d81cac418e3..d310fa3942ce 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -387,7 +387,7 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp);
> void security_cred_free(struct cred *cred);
> int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp);
> void security_transfer_creds(struct cred *new, const struct cred *old);
> -void security_cred_getsecid(const struct cred *c, u32 *secid);
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob);
> int security_kernel_act_as(struct cred *new, struct lsmblob *blob);
> int security_kernel_create_files_as(struct cred *new, struct inode *inode);
> int security_kernel_module_request(char *kmod_name);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index a0205f3c23c7..1b51e907f131 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -137,7 +137,7 @@ static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
> /* The identity of the user shutting down the audit system. */
> kuid_t audit_sig_uid = INVALID_UID;
> pid_t audit_sig_pid = -1;
> -u32 audit_sig_sid = 0;
> +struct lsmblob audit_sig_lsm;
>
> /* Records can be lost in several ways:
> 0) [suppressed in audit_alloc]
> @@ -1429,23 +1429,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
> }
> case AUDIT_SIGNAL_INFO:
> len = 0;
> - if (audit_sig_sid) {
> - struct lsmblob blob;
> -
> - lsmblob_init(&blob, audit_sig_sid);
> - err = security_secid_to_secctx(&blob, &ctx, &len);
> + if (lsmblob_is_set(&audit_sig_lsm)) {
> + err = security_secid_to_secctx(&audit_sig_lsm, &ctx,
> + &len);
> if (err)
> return err;
> }
> sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
> if (!sig_data) {
> - if (audit_sig_sid)
> + if (lsmblob_is_set(&audit_sig_lsm))
> security_release_secctx(ctx, len);
> return -ENOMEM;
> }
> sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
> sig_data->pid = audit_sig_pid;
> - if (audit_sig_sid) {
> + if (lsmblob_is_set(&audit_sig_lsm)) {
> memcpy(sig_data->ctx, ctx, len);
> security_release_secctx(ctx, len);
> }
> diff --git a/kernel/audit.h b/kernel/audit.h
> index 958d5b8fc1b3..29e29c6f4afb 100644
> --- a/kernel/audit.h
> +++ b/kernel/audit.h
> @@ -22,6 +22,7 @@
> #include <linux/fs.h>
> #include <linux/audit.h>
> #include <linux/skbuff.h>
> +#include <linux/security.h>
> #include <uapi/linux/mqueue.h>
> #include <linux/tty.h>
>
> @@ -147,7 +148,7 @@ struct audit_context {
> kuid_t target_auid;
> kuid_t target_uid;
> unsigned int target_sessionid;
> - u32 target_sid;
> + struct lsmblob target_lsm;
> char target_comm[TASK_COMM_LEN];
>
> struct audit_tree_refs *trees, *first_trees;
> @@ -338,7 +339,7 @@ extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
>
> extern pid_t audit_sig_pid;
> extern kuid_t audit_sig_uid;
> -extern u32 audit_sig_sid;
> +extern struct lsmblob audit_sig_lsm;
>
> extern int audit_filter(int msgtype, unsigned int listtype);
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 54797c0fc3b7..c7aa39bda5cc 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -112,7 +112,7 @@ struct audit_aux_data_pids {
> kuid_t target_auid[AUDIT_AUX_PIDS];
> kuid_t target_uid[AUDIT_AUX_PIDS];
> unsigned int target_sessionid[AUDIT_AUX_PIDS];
> - u32 target_sid[AUDIT_AUX_PIDS];
> + struct lsmblob target_lsm[AUDIT_AUX_PIDS];
> char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
> int pid_count;
> };
> @@ -938,14 +938,14 @@ static inline void audit_free_context(struct audit_context *context)
> }
>
> static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> - kuid_t auid, kuid_t uid, unsigned int sessionid,
> - u32 sid, char *comm)
> + kuid_t auid, kuid_t uid,
> + unsigned int sessionid,
> + struct lsmblob *blob, char *comm)
> {
> struct audit_buffer *ab;
> char *ctx = NULL;
> u32 len;
> int rc = 0;
> - struct lsmblob blob;
>
> ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> if (!ab)
> @@ -954,9 +954,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid,
> from_kuid(&init_user_ns, auid),
> from_kuid(&init_user_ns, uid), sessionid);
> - if (sid) {
> - lsmblob_init(&blob, sid);
> - if (security_secid_to_secctx(&blob, &ctx, &len)) {
> + if (lsmblob_is_set(blob)) {
> + if (security_secid_to_secctx(blob, &ctx, &len)) {
> audit_log_format(ab, " obj=(none)");
> rc = 1;
> } else {
> @@ -1527,7 +1526,7 @@ static void audit_log_exit(void)
> axs->target_auid[i],
> axs->target_uid[i],
> axs->target_sessionid[i],
> - axs->target_sid[i],
> + &axs->target_lsm[i],
> axs->target_comm[i]))
> call_panic = 1;
> }
> @@ -1536,7 +1535,7 @@ static void audit_log_exit(void)
> audit_log_pid_context(context, context->target_pid,
> context->target_auid, context->target_uid,
> context->target_sessionid,
> - context->target_sid, context->target_comm))
> + &context->target_lsm, context->target_comm))
> call_panic = 1;
>
> if (context->pwd.dentry && context->pwd.mnt) {
> @@ -1713,7 +1712,7 @@ void __audit_syscall_exit(int success, long return_code)
> context->aux = NULL;
> context->aux_pids = NULL;
> context->target_pid = 0;
> - context->target_sid = 0;
> + lsmblob_init(&context->target_lsm, 0);
> context->sockaddr_len = 0;
> context->type = 0;
> context->fds[0] = -1;
> @@ -2367,15 +2366,12 @@ int __audit_sockaddr(int len, void *a)
> void __audit_ptrace(struct task_struct *t)
> {
> struct audit_context *context = audit_context();
> - struct lsmblob blob;
>
> context->target_pid = task_tgid_nr(t);
> context->target_auid = audit_get_loginuid(t);
> context->target_uid = task_uid(t);
> context->target_sessionid = audit_get_sessionid(t);
> - security_task_getsecid(t, &blob);
> - /* scaffolding - until target_sid is converted */
> - context->target_sid = blob.secid[0];
> + security_task_getsecid(t, &context->target_lsm);
> memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
> }
>
> @@ -2392,7 +2388,6 @@ int audit_signal_info(int sig, struct task_struct *t)
> struct audit_aux_data_pids *axp;
> struct audit_context *ctx = audit_context();
> kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> - struct lsmblob blob;
>
> if (auditd_test_task(t) &&
> (sig == SIGTERM || sig == SIGHUP ||
> @@ -2403,9 +2398,7 @@ int audit_signal_info(int sig, struct task_struct *t)
> audit_sig_uid = auid;
> else
> audit_sig_uid = uid;
> - security_task_getsecid(current, &blob);
> - /* scaffolding until audit_sig_sid is converted */
> - audit_sig_sid = blob.secid[0];
> + security_task_getsecid(current, &audit_sig_lsm);
> }
>
> if (!audit_signals || audit_dummy_context())
> @@ -2418,9 +2411,7 @@ int audit_signal_info(int sig, struct task_struct *t)
> ctx->target_auid = audit_get_loginuid(t);
> ctx->target_uid = t_uid;
> ctx->target_sessionid = audit_get_sessionid(t);
> - security_task_getsecid(t, &blob);
> - /* scaffolding until target_sid is converted */
> - ctx->target_sid = blob.secid[0];
> + security_task_getsecid(t, &ctx->target_lsm);
> memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
> return 0;
> }
> @@ -2441,9 +2432,7 @@ int audit_signal_info(int sig, struct task_struct *t)
> axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
> axp->target_uid[axp->pid_count] = t_uid;
> axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> - security_task_getsecid(t, &blob);
> - /* scaffolding until target_sid is converted */
> - axp->target_sid[axp->pid_count] = blob.secid[0];
> + security_task_getsecid(t, &axp->target_lsm[axp->pid_count]);
> memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
> axp->pid_count++;
>
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index fefa848cf0c7..1afb75a893af 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -363,7 +363,6 @@ int ima_file_mmap(struct file *file, unsigned long prot)
> int ima_bprm_check(struct linux_binprm *bprm)
> {
> int ret;
> - u32 secid;
> struct lsmblob blob;
>
> security_task_getsecid(current, &blob);
> @@ -373,9 +372,10 @@ int ima_bprm_check(struct linux_binprm *bprm)
> if (ret)
> return ret;
>
> - security_cred_getsecid(bprm->cred, &secid);
> - return process_measurement(bprm->file, bprm->cred, secid, NULL, 0,
> - MAY_EXEC, CREDS_CHECK);
> + security_cred_getsecid(bprm->cred, &blob);
> + /* scaffolding until process_measurement changes */
> + return process_measurement(bprm->file, bprm->cred, blob.secid[0],
> + NULL, 0, MAY_EXEC, CREDS_CHECK);
> }
>
> /**
> diff --git a/security/security.c b/security/security.c
> index 91388553d3d7..3180a6f30625 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1627,10 +1627,16 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
> call_void_hook(cred_transfer, new, old);
> }
>
> -void security_cred_getsecid(const struct cred *c, u32 *secid)
> +void security_cred_getsecid(const struct cred *c, struct lsmblob *blob)
> {
> - *secid = 0;
> - call_void_hook(cred_getsecid, c, secid);
> + struct security_hook_list *hp;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.cred_getsecid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + hp->hook.cred_getsecid(c, &blob->secid[hp->lsmid->slot]);
> + }
> }
> EXPORT_SYMBOL(security_cred_getsecid);
>
>
^ permalink raw reply
* Re: [PATCH v4 12/23] LSM: Use lsmblob in security_inode_getsecid
From: John Johansen @ 2019-06-26 23:56 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-13-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change the security_inode_getsecid() interface to fill in a
> lsmblob structure instead of a u32 secid. This allows for its
> callers to gather data from all registered LSMs. Data is provided
> for IMA and audit.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> include/linux/security.h | 7 ++++---
> kernel/auditsc.c | 6 +++++-
> security/integrity/ima/ima_policy.c | 4 +---
> security/security.c | 11 +++++++++--
> 4 files changed, 19 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index cfd7cf4b0be9..2d81cac418e3 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -362,7 +362,7 @@ int security_inode_killpriv(struct dentry *dentry);
> int security_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc);
> int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags);
> int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size);
> -void security_inode_getsecid(struct inode *inode, u32 *secid);
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob);
> int security_inode_copy_up(struct dentry *src, struct cred **new);
> int security_inode_copy_up_xattr(const char *name);
> int security_file_permission(struct file *file, int mask);
> @@ -858,9 +858,10 @@ static inline int security_inode_listsecurity(struct inode *inode, char *buffer,
> return 0;
> }
>
> -static inline void security_inode_getsecid(struct inode *inode, u32 *secid)
> +static inline void security_inode_getsecid(struct inode *inode,
> + struct lsmblob *blob)
> {
> - *secid = 0;
> + lsmblob_init(blob, 0);
> }
>
> static inline int security_inode_copy_up(struct dentry *src, struct cred **new)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 7112fe31684d..54797c0fc3b7 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1910,13 +1910,17 @@ static inline int audit_copy_fcaps(struct audit_names *name,
> void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
> struct inode *inode, unsigned int flags)
> {
> + struct lsmblob blob;
> +
> name->ino = inode->i_ino;
> name->dev = inode->i_sb->s_dev;
> name->mode = inode->i_mode;
> name->uid = inode->i_uid;
> name->gid = inode->i_gid;
> name->rdev = inode->i_rdev;
> - security_inode_getsecid(inode, &name->osid);
> + security_inode_getsecid(inode, &blob);
> + /* scaffolding until osid is updated */
> + name->osid = blob.secid[0];
> if (flags & AUDIT_INODE_NOEVAL) {
> name->fcap_ver = -1;
> return;
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index e7b8ce942950..92ee3d984c73 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -326,7 +326,6 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> return false;
> for (i = 0; i < MAX_LSM_RULES; i++) {
> int rc = 0;
> - u32 osid;
> struct lsmblob blob;
> int retried = 0;
>
> @@ -337,8 +336,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
> case LSM_OBJ_USER:
> case LSM_OBJ_ROLE:
> case LSM_OBJ_TYPE:
> - security_inode_getsecid(inode, &osid);
> - lsmblob_init(&blob, osid);
> + security_inode_getsecid(inode, &blob);
> rc = security_filter_rule_match(&blob,
> rule->lsm[i].type,
> Audit_equal,
> diff --git a/security/security.c b/security/security.c
> index 2f123003b0b3..91388553d3d7 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1404,9 +1404,16 @@ int security_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer
> }
> EXPORT_SYMBOL(security_inode_listsecurity);
>
> -void security_inode_getsecid(struct inode *inode, u32 *secid)
> +void security_inode_getsecid(struct inode *inode, struct lsmblob *blob)
> {
> - call_void_hook(inode_getsecid, inode, secid);
> + struct security_hook_list *hp;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.inode_getsecid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + hp->hook.inode_getsecid(inode, &blob->secid[hp->lsmid->slot]);
> + }
> }
>
> int security_inode_copy_up(struct dentry *src, struct cred **new)
>
^ permalink raw reply
* Re: [PATCH v4 11/23] LSM: Use lsmblob in security_task_getsecid
From: John Johansen @ 2019-06-26 23:55 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-12-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change the security_task_getsecid() interface to fill in
> a lsmblob structure instead of a u32 secid in support of
> LSM stacking. Audit interfaces will need to collect all
> possible secids for possible reporting.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> drivers/android/binder.c | 4 +---
> include/linux/security.h | 7 +++---
> kernel/audit.c | 6 ++---
> kernel/auditfilter.c | 4 +---
> kernel/auditsc.c | 22 ++++++++++++------
> net/netlabel/netlabel_unlabeled.c | 5 +++-
> net/netlabel/netlabel_user.h | 6 ++++-
> security/integrity/ima/ima_appraise.c | 4 +++-
> security/integrity/ima/ima_main.c | 33 +++++++++++++++------------
> security/security.c | 12 +++++++---
> 10 files changed, 63 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 1962f6b8abd0..144ac4f1c24f 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3119,11 +3119,9 @@ static void binder_transaction(struct binder_proc *proc,
> t->priority = task_nice(current);
>
> if (target_node && target_node->txn_security_ctx) {
> - u32 secid;
> struct lsmblob blob;
>
> - security_task_getsecid(proc->tsk, &secid);
> - lsmblob_init(&blob, secid);
> + security_task_getsecid(proc->tsk, &blob);
> ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> if (ret) {
> return_error = BR_FAILED_REPLY;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 41dc3053094e..cfd7cf4b0be9 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -400,7 +400,7 @@ int security_task_fix_setuid(struct cred *new, const struct cred *old,
> int security_task_setpgid(struct task_struct *p, pid_t pgid);
> int security_task_getpgid(struct task_struct *p);
> int security_task_getsid(struct task_struct *p);
> -void security_task_getsecid(struct task_struct *p, u32 *secid);
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob);
> int security_task_setnice(struct task_struct *p, int nice);
> int security_task_setioprio(struct task_struct *p, int ioprio);
> int security_task_getioprio(struct task_struct *p);
> @@ -1029,9 +1029,10 @@ static inline int security_task_getsid(struct task_struct *p)
> return 0;
> }
>
> -static inline void security_task_getsecid(struct task_struct *p, u32 *secid)
> +static inline void security_task_getsecid(struct task_struct *p,
> + struct lsmblob *blob)
> {
> - *secid = 0;
> + lsmblob_init(blob, 0);
> }
>
> static inline int security_task_setnice(struct task_struct *p, int nice)
> diff --git a/kernel/audit.c b/kernel/audit.c
> index d0338411d75d..a0205f3c23c7 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2075,14 +2075,12 @@ int audit_log_task_context(struct audit_buffer *ab)
> char *ctx = NULL;
> unsigned len;
> int error;
> - u32 sid;
> struct lsmblob blob;
>
> - security_task_getsecid(current, &sid);
> - if (!sid)
> + security_task_getsecid(current, &blob);
> + if (!lsmblob_is_set(&blob))
> return 0;
>
> - lsmblob_init(&blob, sid);
> error = security_secid_to_secctx(&blob, &ctx, &len);
> if (error) {
> if (error != -EINVAL)
> diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
> index 8786b95b60bd..8f244c98bb57 100644
> --- a/kernel/auditfilter.c
> +++ b/kernel/auditfilter.c
> @@ -1323,7 +1323,6 @@ int audit_filter(int msgtype, unsigned int listtype)
> for (i = 0; i < e->rule.field_count; i++) {
> struct audit_field *f = &e->rule.fields[i];
> pid_t pid;
> - u32 sid;
> struct lsmblob blob;
>
> switch (f->type) {
> @@ -1354,8 +1353,7 @@ int audit_filter(int msgtype, unsigned int listtype)
> case AUDIT_SUBJ_SEN:
> case AUDIT_SUBJ_CLR:
> if (f->lsm_rule) {
> - security_task_getsecid(current, &sid);
> - lsmblob_init(&blob, sid);
> + security_task_getsecid(current, &blob);
> result = security_audit_rule_match(
> &blob, f->type,
> f->op, f->lsm_rule);
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 148733ec3c72..7112fe31684d 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -444,7 +444,6 @@ static int audit_filter_rules(struct task_struct *tsk,
> {
> const struct cred *cred;
> int i, need_sid = 1;
> - u32 sid;
> struct lsmblob blob;
> unsigned int sessionid;
>
> @@ -628,10 +627,9 @@ static int audit_filter_rules(struct task_struct *tsk,
> logged upon error */
> if (f->lsm_rule) {
> if (need_sid) {
> - security_task_getsecid(tsk, &sid);
> + security_task_getsecid(tsk, &blob);
> need_sid = 0;
> }
> - lsmblob_init(&blob, sid);
> result = security_audit_rule_match(&blob,
> f->type,
> f->op,
> @@ -2365,12 +2363,15 @@ int __audit_sockaddr(int len, void *a)
> void __audit_ptrace(struct task_struct *t)
> {
> struct audit_context *context = audit_context();
> + struct lsmblob blob;
>
> context->target_pid = task_tgid_nr(t);
> context->target_auid = audit_get_loginuid(t);
> context->target_uid = task_uid(t);
> context->target_sessionid = audit_get_sessionid(t);
> - security_task_getsecid(t, &context->target_sid);
> + security_task_getsecid(t, &blob);
> + /* scaffolding - until target_sid is converted */
> + context->target_sid = blob.secid[0];
> memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
> }
>
> @@ -2387,6 +2388,7 @@ int audit_signal_info(int sig, struct task_struct *t)
> struct audit_aux_data_pids *axp;
> struct audit_context *ctx = audit_context();
> kuid_t uid = current_uid(), auid, t_uid = task_uid(t);
> + struct lsmblob blob;
>
> if (auditd_test_task(t) &&
> (sig == SIGTERM || sig == SIGHUP ||
> @@ -2397,7 +2399,9 @@ int audit_signal_info(int sig, struct task_struct *t)
> audit_sig_uid = auid;
> else
> audit_sig_uid = uid;
> - security_task_getsecid(current, &audit_sig_sid);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until audit_sig_sid is converted */
> + audit_sig_sid = blob.secid[0];
> }
>
> if (!audit_signals || audit_dummy_context())
> @@ -2410,7 +2414,9 @@ int audit_signal_info(int sig, struct task_struct *t)
> ctx->target_auid = audit_get_loginuid(t);
> ctx->target_uid = t_uid;
> ctx->target_sessionid = audit_get_sessionid(t);
> - security_task_getsecid(t, &ctx->target_sid);
> + security_task_getsecid(t, &blob);
> + /* scaffolding until target_sid is converted */
> + ctx->target_sid = blob.secid[0];
> memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
> return 0;
> }
> @@ -2431,7 +2437,9 @@ int audit_signal_info(int sig, struct task_struct *t)
> axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
> axp->target_uid[axp->pid_count] = t_uid;
> axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
> - security_task_getsecid(t, &axp->target_sid[axp->pid_count]);
> + security_task_getsecid(t, &blob);
> + /* scaffolding until target_sid is converted */
> + axp->target_sid[axp->pid_count] = blob.secid[0];
> memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
> axp->pid_count++;
>
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2d8dd5b84457..2294aa9471e6 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -1552,11 +1552,14 @@ int __init netlbl_unlabel_defconf(void)
> int ret_val;
> struct netlbl_dom_map *entry;
> struct netlbl_audit audit_info;
> + struct lsmblob blob;
>
> /* Only the kernel is allowed to call this function and the only time
> * it is called is at bootup before the audit subsystem is reporting
> * messages so don't worry to much about these values. */
> - security_task_getsecid(current, &audit_info.secid);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until audit_info.secid is converted */
> + audit_info.secid = blob.secid[0];
> audit_info.loginuid = GLOBAL_ROOT_UID;
> audit_info.sessionid = 0;
>
> diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
> index 4a397cde1a48..ab88baaaa50d 100644
> --- a/net/netlabel/netlabel_user.h
> +++ b/net/netlabel/netlabel_user.h
> @@ -48,7 +48,11 @@
> static inline void netlbl_netlink_auditinfo(struct sk_buff *skb,
> struct netlbl_audit *audit_info)
> {
> - security_task_getsecid(current, &audit_info->secid);
> + struct lsmblob blob;
> +
> + security_task_getsecid(current, &blob);
> + /* scaffolding until secid is converted */
> + audit_info->secid = blob.secid[0];
> audit_info->loginuid = audit_get_loginuid(current);
> audit_info->sessionid = audit_get_sessionid(current);
> }
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 5fb7127bbe68..85c7692fc4a3 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -51,11 +51,13 @@ bool is_ima_appraise_enabled(void)
> int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func)
> {
> u32 secid;
> + struct lsmblob blob;
>
> if (!ima_appraise)
> return 0;
>
> - security_task_getsecid(current, &secid);
> + security_task_getsecid(current, &blob);
> + lsmblob_secid(&blob, &secid);
> return ima_match_policy(inode, current_cred(), secid, func, mask,
> IMA_APPRAISE | IMA_HASH, NULL);
> }
> diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
> index 357edd140c09..fefa848cf0c7 100644
> --- a/security/integrity/ima/ima_main.c
> +++ b/security/integrity/ima/ima_main.c
> @@ -335,12 +335,13 @@ static int process_measurement(struct file *file, const struct cred *cred,
> */
> int ima_file_mmap(struct file *file, unsigned long prot)
> {
> - u32 secid;
> + struct lsmblob blob;
>
> if (file && (prot & PROT_EXEC)) {
> - security_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, NULL,
> - 0, MAY_EXEC, MMAP_CHECK);
> + security_task_getsecid(current, &blob);
> + /* scaffolding - until process_measurement changes */
> + return process_measurement(file, current_cred(), blob.secid[0],
> + NULL, 0, MAY_EXEC, MMAP_CHECK);
> }
>
> return 0;
> @@ -363,10 +364,12 @@ int ima_bprm_check(struct linux_binprm *bprm)
> {
> int ret;
> u32 secid;
> + struct lsmblob blob;
>
> - security_task_getsecid(current, &secid);
> - ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0,
> - MAY_EXEC, BPRM_CHECK);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until process_measurement changes */
> + ret = process_measurement(bprm->file, current_cred(), blob.secid[0],
> + NULL, 0, MAY_EXEC, BPRM_CHECK);
> if (ret)
> return ret;
>
> @@ -387,10 +390,11 @@ int ima_bprm_check(struct linux_binprm *bprm)
> */
> int ima_file_check(struct file *file, int mask)
> {
> - u32 secid;
> + struct lsmblob blob;
>
> - security_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, NULL, 0,
> + security_task_getsecid(current, &blob);
> + /* scaffolding until process_measurement changes */
> + return process_measurement(file, current_cred(), blob.secid[0], NULL, 0,
> mask & (MAY_READ | MAY_WRITE | MAY_EXEC |
> MAY_APPEND), FILE_CHECK);
> }
> @@ -499,7 +503,7 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
> enum kernel_read_file_id read_id)
> {
> enum ima_hooks func;
> - u32 secid;
> + struct lsmblob blob;
>
> if (!file && read_id == READING_FIRMWARE) {
> if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
> @@ -521,9 +525,10 @@ int ima_post_read_file(struct file *file, void *buf, loff_t size,
> }
>
> func = read_idmap[read_id] ?: FILE_CHECK;
> - security_task_getsecid(current, &secid);
> - return process_measurement(file, current_cred(), secid, buf, size,
> - MAY_READ, func);
> + security_task_getsecid(current, &blob);
> + /* scaffolding until process_measurement changes */
> + return process_measurement(file, current_cred(), blob.secid[0], buf,
> + size, MAY_READ, func);
> }
>
> /**
> diff --git a/security/security.c b/security/security.c
> index 5245d4d1e799..2f123003b0b3 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1712,10 +1712,16 @@ int security_task_getsid(struct task_struct *p)
> return call_int_hook(task_getsid, 0, p);
> }
>
> -void security_task_getsecid(struct task_struct *p, u32 *secid)
> +void security_task_getsecid(struct task_struct *p, struct lsmblob *blob)
> {
> - *secid = 0;
> - call_void_hook(task_getsecid, p, secid);
> + struct security_hook_list *hp;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.task_getsecid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + hp->hook.task_getsecid(p, &blob->secid[hp->lsmid->slot]);
> + }
> }
> EXPORT_SYMBOL(security_task_getsecid);
>
>
^ permalink raw reply
* Re: [PATCH v4 10/23] LSM: Use lsmblob in security_ipc_getsecid
From: John Johansen @ 2019-06-26 23:53 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-11-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> There may be more than one LSM that provides IPC data
> for auditing. Change security_ipc_getsecid() to fill in
> a lsmblob structure instead of the u32 secid. The
> audit data structure containing the secid will be updated
> later, so there is a bit of scaffolding here.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> include/linux/security.h | 7 ++++---
> kernel/auditsc.c | 5 ++++-
> security/security.c | 12 +++++++++---
> 3 files changed, 17 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 7b4667cc4930..41dc3053094e 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -417,7 +417,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
> unsigned long arg4, unsigned long arg5);
> void security_task_to_inode(struct task_struct *p, struct inode *inode);
> int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob);
> int security_msg_msg_alloc(struct msg_msg *msg);
> void security_msg_msg_free(struct msg_msg *msg);
> int security_msg_queue_alloc(struct kern_ipc_perm *msq);
> @@ -1102,9 +1102,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
> return 0;
> }
>
> -static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
> + struct lsmblob *blob)
> {
> - *secid = 0;
> + lsmblob_init(blob, 0);
> }
>
> static inline int security_msg_msg_alloc(struct msg_msg *msg)
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index d31914088a82..148733ec3c72 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2268,11 +2268,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
> void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
> {
> struct audit_context *context = audit_context();
> + struct lsmblob blob;
> context->ipc.uid = ipcp->uid;
> context->ipc.gid = ipcp->gid;
> context->ipc.mode = ipcp->mode;
> context->ipc.has_perm = 0;
> - security_ipc_getsecid(ipcp, &context->ipc.osid);
> + security_ipc_getsecid(ipcp, &blob);
> + /* scaffolding on the [0] - change "osid" to a lsmblob */
> + context->ipc.osid = blob.secid[0];
> context->type = AUDIT_IPC;
> }
>
> diff --git a/security/security.c b/security/security.c
> index 0c7784a243e7..5245d4d1e799 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1795,10 +1795,16 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
> return call_int_hook(ipc_permission, 0, ipcp, flag);
> }
>
> -void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
> +void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *blob)
> {
> - *secid = 0;
> - call_void_hook(ipc_getsecid, ipcp, secid);
> + struct security_hook_list *hp;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + hp->hook.ipc_getsecid(ipcp, &blob->secid[hp->lsmid->slot]);
> + }
> }
>
> int security_msg_msg_alloc(struct msg_msg *msg)
>
^ permalink raw reply
* Re: [PATCH v4 09/23] LSM: Use lsmblob in security_secid_to_secctx
From: John Johansen @ 2019-06-26 23:51 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-10-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change security_secid_to_secctx() to take a lsmblob as input
> instead of a u32 secid. It will then call the LSM hooks
> using the lsmblob element allocated for that module. The
> callers have been updated as well. This allows for the
> possibility that more than one module may be called upon
> to translate a secid to a string, as can occur in the
> audit code.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> drivers/android/binder.c | 4 +++-
> include/linux/security.h | 5 +++--
> include/net/scm.h | 5 ++---
> kernel/audit.c | 9 +++++++--
> kernel/auditsc.c | 14 ++++++++++----
> net/ipv4/ip_sockglue.c | 3 +--
> net/netfilter/nf_conntrack_netlink.c | 8 ++++++--
> net/netfilter/nf_conntrack_standalone.c | 4 +++-
> net/netfilter/nfnetlink_queue.c | 8 ++++++--
> net/netlabel/netlabel_unlabeled.c | 18 ++++++++++++++----
> net/netlabel/netlabel_user.c | 6 +++---
> security/security.c | 16 +++++++++++++---
> 12 files changed, 71 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 8685882da64c..1962f6b8abd0 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -3120,9 +3120,11 @@ static void binder_transaction(struct binder_proc *proc,
>
> if (target_node && target_node->txn_security_ctx) {
> u32 secid;
> + struct lsmblob blob;
>
> security_task_getsecid(proc->tsk, &secid);
> - ret = security_secid_to_secctx(secid, &secctx, &secctx_sz);
> + lsmblob_init(&blob, secid);
> + ret = security_secid_to_secctx(&blob, &secctx, &secctx_sz);
> if (ret) {
> return_error = BR_FAILED_REPLY;
> return_error_param = ret;
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 30337f1a9056..7b4667cc4930 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -446,7 +446,7 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> size_t size);
> int security_netlink_send(struct sock *sk, struct sk_buff *skb);
> int security_ismaclabel(const char *name);
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen);
> int security_secctx_to_secid(const char *secdata, u32 seclen,
> struct lsmblob *blob);
> void security_release_secctx(char *secdata, u32 seclen);
> @@ -1224,7 +1224,8 @@ static inline int security_ismaclabel(const char *name)
> return 0;
> }
>
> -static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +static inline int security_secid_to_secctx(struct lsmblob *blob,
> + char **secdata, u32 *seclen)
> {
> return -EOPNOTSUPP;
> }
> diff --git a/include/net/scm.h b/include/net/scm.h
> index e2e71c4bf9d0..31ae605fcc0a 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -97,9 +97,8 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
> int err;
>
> if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> - /* Scaffolding - it has to be element 0 for now */
> - err = security_secid_to_secctx(scm->lsmblob.secid[0],
> - &secdata, &seclen);
> + err = security_secid_to_secctx(&scm->lsmblob, &secdata,
> + &seclen);
>
> if (!err) {
> put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/kernel/audit.c b/kernel/audit.c
> index c89ea48c70a6..d0338411d75d 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -1430,7 +1430,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
> case AUDIT_SIGNAL_INFO:
> len = 0;
> if (audit_sig_sid) {
> - err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
> + struct lsmblob blob;
> +
> + lsmblob_init(&blob, audit_sig_sid);
> + err = security_secid_to_secctx(&blob, &ctx, &len);
> if (err)
> return err;
> }
> @@ -2073,12 +2076,14 @@ int audit_log_task_context(struct audit_buffer *ab)
> unsigned len;
> int error;
> u32 sid;
> + struct lsmblob blob;
>
> security_task_getsecid(current, &sid);
> if (!sid)
> return 0;
>
> - error = security_secid_to_secctx(sid, &ctx, &len);
> + lsmblob_init(&blob, sid);
> + error = security_secid_to_secctx(&blob, &ctx, &len);
> if (error) {
> if (error != -EINVAL)
> goto error_path;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 18ee5556c086..d31914088a82 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -947,6 +947,7 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> char *ctx = NULL;
> u32 len;
> int rc = 0;
> + struct lsmblob blob;
>
> ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
> if (!ab)
> @@ -956,7 +957,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
> from_kuid(&init_user_ns, auid),
> from_kuid(&init_user_ns, uid), sessionid);
> if (sid) {
> - if (security_secid_to_secctx(sid, &ctx, &len)) {
> + lsmblob_init(&blob, sid);
> + if (security_secid_to_secctx(&blob, &ctx, &len)) {
> audit_log_format(ab, " obj=(none)");
> rc = 1;
> } else {
> @@ -1198,7 +1200,10 @@ static void show_special(struct audit_context *context, int *call_panic)
> if (osid) {
> char *ctx = NULL;
> u32 len;
> - if (security_secid_to_secctx(osid, &ctx, &len)) {
> + struct lsmblob blob;
> +
> + lsmblob_init(&blob, osid);
> + if (security_secid_to_secctx(&blob, &ctx, &len)) {
> audit_log_format(ab, " osid=%u", osid);
> *call_panic = 1;
> } else {
> @@ -1349,9 +1354,10 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
> if (n->osid != 0) {
> char *ctx = NULL;
> u32 len;
> + struct lsmblob blob;
>
> - if (security_secid_to_secctx(
> - n->osid, &ctx, &len)) {
> + lsmblob_init(&blob, n->osid);
> + if (security_secid_to_secctx(&blob, &ctx, &len)) {
> audit_log_format(ab, " osid=%u", n->osid);
> if (call_panic)
> *call_panic = 2;
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 2a5c868ce135..e05f4ef68bd8 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -139,8 +139,7 @@ static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
> if (err)
> return;
>
> - /* Scaffolding - it has to be element 0 */
> - err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
> + err = security_secid_to_secctx(&lb, &secdata, &seclen);
> if (err)
> return;
>
> diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
> index 66c596d287a5..ca0968f13240 100644
> --- a/net/netfilter/nf_conntrack_netlink.c
> +++ b/net/netfilter/nf_conntrack_netlink.c
> @@ -330,8 +330,10 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
> struct nlattr *nest_secctx;
> int len, ret;
> char *secctx;
> + struct lsmblob blob;
>
> - ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> + lsmblob_init(&blob, ct->secmark);
> + ret = security_secid_to_secctx(&blob, &secctx, &len);
> if (ret)
> return 0;
>
> @@ -615,8 +617,10 @@ static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
> {
> #ifdef CONFIG_NF_CONNTRACK_SECMARK
> int len, ret;
> + struct lsmblob blob;
>
> - ret = security_secid_to_secctx(ct->secmark, NULL, &len);
> + lsmblob_init(&blob, ct->secmark);
> + ret = security_secid_to_secctx(&blob, NULL, &len);
> if (ret)
> return 0;
>
> diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
> index c2ae14c720b4..c793103f3cd7 100644
> --- a/net/netfilter/nf_conntrack_standalone.c
> +++ b/net/netfilter/nf_conntrack_standalone.c
> @@ -175,8 +175,10 @@ static void ct_show_secctx(struct seq_file *s, const struct nf_conn *ct)
> int ret;
> u32 len;
> char *secctx;
> + struct lsmblob blob;
>
> - ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
> + lsmblob_init(&blob, ct->secmark);
> + ret = security_secid_to_secctx(&blob, &secctx, &len);
> if (ret)
> return;
>
> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
> index 0dcc3592d053..59211bff90ab 100644
> --- a/net/netfilter/nfnetlink_queue.c
> +++ b/net/netfilter/nfnetlink_queue.c
> @@ -309,13 +309,17 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata)
> {
> u32 seclen = 0;
> #if IS_ENABLED(CONFIG_NETWORK_SECMARK)
> + struct lsmblob blob;
> +
> if (!skb || !sk_fullsock(skb->sk))
> return 0;
>
> read_lock_bh(&skb->sk->sk_callback_lock);
>
> - if (skb->secmark)
> - security_secid_to_secctx(skb->secmark, secdata, &seclen);
> + if (skb->secmark) {
> + lsmblob_init(&blob, skb->secmark);
> + security_secid_to_secctx(&blob, secdata, &seclen);
> + }
>
> read_unlock_bh(&skb->sk->sk_callback_lock);
> #endif
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index 2976370e41aa..2d8dd5b84457 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -389,6 +389,7 @@ int netlbl_unlhsh_add(struct net *net,
> struct audit_buffer *audit_buf = NULL;
> char *secctx = NULL;
> u32 secctx_len;
> + struct lsmblob blob;
>
> if (addr_len != sizeof(struct in_addr) &&
> addr_len != sizeof(struct in6_addr))
> @@ -451,7 +452,8 @@ int netlbl_unlhsh_add(struct net *net,
> unlhsh_add_return:
> rcu_read_unlock();
> if (audit_buf != NULL) {
> - if (security_secid_to_secctx(secid,
> + lsmblob_init(&blob, secid);
> + if (security_secid_to_secctx(&blob,
> &secctx,
> &secctx_len) == 0) {
> audit_log_format(audit_buf, " sec_obj=%s", secctx);
> @@ -488,6 +490,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
> struct net_device *dev;
> char *secctx;
> u32 secctx_len;
> + struct lsmblob blob;
>
> spin_lock(&netlbl_unlhsh_lock);
> list_entry = netlbl_af4list_remove(addr->s_addr, mask->s_addr,
> @@ -507,8 +510,10 @@ static int netlbl_unlhsh_remove_addr4(struct net *net,
> addr->s_addr, mask->s_addr);
> if (dev != NULL)
> dev_put(dev);
> + if (entry != NULL)
> + lsmblob_init(&blob, entry->secid);
> if (entry != NULL &&
> - security_secid_to_secctx(entry->secid,
> + security_secid_to_secctx(&blob,
> &secctx, &secctx_len) == 0) {
> audit_log_format(audit_buf, " sec_obj=%s", secctx);
> security_release_secctx(secctx, secctx_len);
> @@ -550,6 +555,7 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
> struct net_device *dev;
> char *secctx;
> u32 secctx_len;
> + struct lsmblob blob;
>
> spin_lock(&netlbl_unlhsh_lock);
> list_entry = netlbl_af6list_remove(addr, mask, &iface->addr6_list);
> @@ -568,8 +574,10 @@ static int netlbl_unlhsh_remove_addr6(struct net *net,
> addr, mask);
> if (dev != NULL)
> dev_put(dev);
> + if (entry != NULL)
> + lsmblob_init(&blob, entry->secid);
> if (entry != NULL &&
> - security_secid_to_secctx(entry->secid,
> + security_secid_to_secctx(&blob,
> &secctx, &secctx_len) == 0) {
> audit_log_format(audit_buf, " sec_obj=%s", secctx);
> security_release_secctx(secctx, secctx_len);
> @@ -1090,6 +1098,7 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
> u32 secid;
> char *secctx;
> u32 secctx_len;
> + struct lsmblob blob;
>
> data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).portid,
> cb_arg->seq, &netlbl_unlabel_gnl_family,
> @@ -1144,7 +1153,8 @@ static int netlbl_unlabel_staticlist_gen(u32 cmd,
> secid = addr6->secid;
> }
>
> - ret_val = security_secid_to_secctx(secid, &secctx, &secctx_len);
> + lsmblob_init(&blob, secid);
> + ret_val = security_secid_to_secctx(&blob, &secctx, &secctx_len);
> if (ret_val != 0)
> goto list_cb_failure;
> ret_val = nla_put(cb_arg->skb,
> diff --git a/net/netlabel/netlabel_user.c b/net/netlabel/netlabel_user.c
> index 4676f5bb16ae..2ccc6567e2a2 100644
> --- a/net/netlabel/netlabel_user.c
> +++ b/net/netlabel/netlabel_user.c
> @@ -100,6 +100,7 @@ struct audit_buffer *netlbl_audit_start_common(int type,
> struct audit_buffer *audit_buf;
> char *secctx;
> u32 secctx_len;
> + struct lsmblob blob;
>
> if (audit_enabled == AUDIT_OFF)
> return NULL;
> @@ -112,10 +113,9 @@ struct audit_buffer *netlbl_audit_start_common(int type,
> from_kuid(&init_user_ns, audit_info->loginuid),
> audit_info->sessionid);
>
> + lsmblob_init(&blob, audit_info->secid);
> if (audit_info->secid != 0 &&
> - security_secid_to_secctx(audit_info->secid,
> - &secctx,
> - &secctx_len) == 0) {
> + security_secid_to_secctx(&blob, &secctx, &secctx_len) == 0) {
> audit_log_format(audit_buf, " subj=%s", secctx);
> security_release_secctx(secctx, secctx_len);
> }
> diff --git a/security/security.c b/security/security.c
> index ad9aaa46ed04..0c7784a243e7 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1975,10 +1975,20 @@ int security_ismaclabel(const char *name)
> }
> EXPORT_SYMBOL(security_ismaclabel);
>
> -int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> +int security_secid_to_secctx(struct lsmblob *blob, char **secdata, u32 *seclen)
> {
> - return call_int_hook(secid_to_secctx, -EOPNOTSUPP, secid, secdata,
> - seclen);
> + struct security_hook_list *hp;
> + int rc;
> +
> + hlist_for_each_entry(hp, &security_hook_heads.secid_to_secctx, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + rc = hp->hook.secid_to_secctx(blob->secid[hp->lsmid->slot],
> + secdata, seclen);
> + if (rc != 0)
> + return rc;
> + }
> + return 0;
> }
> EXPORT_SYMBOL(security_secid_to_secctx);
>
>
^ permalink raw reply
* Re: [PATCH v4 08/23] LSM: Use lsmblob in security_secctx_to_secid
From: John Johansen @ 2019-06-26 23:50 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-9-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change security_secctx_to_secid() to fill in a lsmblob instead
> of a u32 secid. Multiple LSMs may be able to interpret the
> string, and this allows for setting whichever secid is
> appropriate. In some cases there is scaffolding where other
> interfaces have yet to be converted.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> include/linux/security.h | 5 +++--
> kernel/cred.c | 4 +---
> net/netfilter/nft_meta.c | 13 ++++++-------
> net/netfilter/xt_SECMARK.c | 5 ++++-
> net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
> security/security.c | 18 +++++++++++++++---
> 6 files changed, 37 insertions(+), 22 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index dcf20da87d1b..30337f1a9056 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -447,7 +447,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
> int security_netlink_send(struct sock *sk, struct sk_buff *skb);
> int security_ismaclabel(const char *name);
> int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> + struct lsmblob *blob);
> void security_release_secctx(char *secdata, u32 seclen);
>
> void security_inode_invalidate_secctx(struct inode *inode);
> @@ -1230,7 +1231,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
>
> static inline int security_secctx_to_secid(const char *secdata,
> u32 seclen,
> - u32 *secid)
> + struct lsmblob *blob)
> {
> return -EOPNOTSUPP;
> }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 71c14dda107e..d70a2c02ced4 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -725,14 +725,12 @@ EXPORT_SYMBOL(set_security_override);
> int set_security_override_from_ctx(struct cred *new, const char *secctx)
> {
> struct lsmblob blob;
> - u32 secid;
> int ret;
>
> - ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
> + ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
> if (ret < 0)
> return ret;
>
> - lsmblob_init(&blob, secid);
> return set_security_override(new, &blob);
> }
> EXPORT_SYMBOL(set_security_override_from_ctx);
> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 987d2d6ce624..054fb4b48d51 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -576,21 +576,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
>
> static int nft_secmark_compute_secid(struct nft_secmark *priv)
> {
> - u32 tmp_secid = 0;
> + struct lsmblob blob;
> int err;
>
> - err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
> + err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
> if (err)
> return err;
>
> - if (!tmp_secid)
> - return -ENOENT;
> -
> - err = security_secmark_relabel_packet(tmp_secid);
> + /* Using le[0] is scaffolding */
> + err = security_secmark_relabel_packet(blob.secid[0]);
> if (err)
> return err;
>
> - priv->secid = tmp_secid;
> + /* Using le[0] is scaffolding */
> + priv->secid = blob.secid[0];
> return 0;
> }
>
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index f16202d26c20..8081fadc30e9 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -49,13 +49,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
>
> static int checkentry_lsm(struct xt_secmark_target_info *info)
> {
> + struct lsmblob blob;
> int err;
>
> info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
> info->secid = 0;
>
> err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
> - &info->secid);
> + &blob);
> if (err) {
> if (err == -EINVAL)
> pr_info_ratelimited("invalid security context \'%s\'\n",
> @@ -63,6 +64,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
> return err;
> }
>
> + /* scaffolding during the transition */
> + info->secid = blob.secid[0];
> if (!info->secid) {
> pr_info_ratelimited("unable to map security context \'%s\'\n",
> info->secctx);
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index c92894c3e40a..2976370e41aa 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -895,7 +895,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
> void *addr;
> void *mask;
> u32 addr_len;
> - u32 secid;
> + struct lsmblob blob;
> struct netlbl_audit audit_info;
>
> /* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -919,12 +919,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
> ret_val = security_secctx_to_secid(
> nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> - &secid);
> + &blob);
> if (ret_val != 0)
> return ret_val;
>
> + /* scaffolding with the [0] */
> return netlbl_unlhsh_add(&init_net,
> - dev_name, addr, mask, addr_len, secid,
> + dev_name, addr, mask, addr_len, blob.secid[0],
> &audit_info);
> }
>
> @@ -946,7 +947,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
> void *addr;
> void *mask;
> u32 addr_len;
> - u32 secid;
> + struct lsmblob blob;
> struct netlbl_audit audit_info;
>
> /* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -968,12 +969,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
> ret_val = security_secctx_to_secid(
> nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> - &secid);
> + &blob);
> if (ret_val != 0)
> return ret_val;
>
> + /* scaffolding with the [0] */
> return netlbl_unlhsh_add(&init_net,
> - NULL, addr, mask, addr_len, secid,
> + NULL, addr, mask, addr_len, blob.secid[0],
> &audit_info);
> }
>
> diff --git a/security/security.c b/security/security.c
> index 4e1eb2a54064..ad9aaa46ed04 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1982,10 +1982,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
> }
> EXPORT_SYMBOL(security_secid_to_secctx);
>
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> + struct lsmblob *blob)
> {
> - *secid = 0;
> - return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
> + struct security_hook_list *hp;
> + int rc;
> +
> + lsmblob_init(blob, 0);
> + hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + rc = hp->hook.secctx_to_secid(secdata, seclen,
> + &blob->secid[hp->lsmid->slot]);
> + if (rc != 0)
> + return rc;
> + }
> + return 0;
> }
> EXPORT_SYMBOL(security_secctx_to_secid);
>
>
^ permalink raw reply
* Re: [PATCH v4 07/23] net: Prepare UDS for secuirty module stacking
From: John Johansen @ 2019-06-26 23:48 UTC (permalink / raw)
To: Casey Schaufler, casey.schaufler, jmorris, linux-security-module,
selinux
Cc: keescook, penguin-kernel, paul, sds
In-Reply-To: <20190626192234.11725-8-casey@schaufler-ca.com>
On 6/26/19 12:22 PM, Casey Schaufler wrote:
> Change the data used in UDS SO_PEERSEC processing from a
> secid to a more general struct lsmblob. Update the
> security_socket_getpeersec_dgram() interface to use the
> lsmblob. There is a small amount of scaffolding code
> that will come out when the security_secid_to_secctx()
> code is brought in line with the lsmblob.
>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
> ---
> include/linux/security.h | 7 +++++--
> include/net/af_unix.h | 2 +-
> include/net/scm.h | 8 +++++---
> net/ipv4/ip_sockglue.c | 8 +++++---
> net/unix/af_unix.c | 6 +++---
> security/security.c | 18 +++++++++++++++---
> 6 files changed, 34 insertions(+), 15 deletions(-)
>
> diff --git a/include/linux/security.h b/include/linux/security.h
> index 313e45a3cac3..dcf20da87d1b 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -1280,7 +1280,8 @@ int security_socket_shutdown(struct socket *sock, int how);
> int security_sock_rcv_skb(struct sock *sk, struct sk_buff *skb);
> int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> int __user *optlen, unsigned len);
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid);
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> + struct lsmblob *blob);
> int security_sk_alloc(struct sock *sk, int family, gfp_t priority);
> void security_sk_free(struct sock *sk);
> void security_sk_clone(const struct sock *sk, struct sock *newsk);
> @@ -1418,7 +1419,9 @@ static inline int security_socket_getpeersec_stream(struct socket *sock, char __
> return -ENOPROTOOPT;
> }
>
> -static inline int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +static inline int security_socket_getpeersec_dgram(struct socket *sock,
> + struct sk_buff *skb,
> + struct lsmblob *blob)
> {
> return -ENOPROTOOPT;
> }
> diff --git a/include/net/af_unix.h b/include/net/af_unix.h
> index 3426d6dacc45..933492c08b8c 100644
> --- a/include/net/af_unix.h
> +++ b/include/net/af_unix.h
> @@ -36,7 +36,7 @@ struct unix_skb_parms {
> kgid_t gid;
> struct scm_fp_list *fp; /* Passed files */
> #ifdef CONFIG_SECURITY_NETWORK
> - u32 secid; /* Security ID */
> + struct lsmblob lsmblob; /* Security LSM data */
> #endif
> u32 consumed;
> } __randomize_layout;
> diff --git a/include/net/scm.h b/include/net/scm.h
> index 1ce365f4c256..e2e71c4bf9d0 100644
> --- a/include/net/scm.h
> +++ b/include/net/scm.h
> @@ -33,7 +33,7 @@ struct scm_cookie {
> struct scm_fp_list *fp; /* Passed files */
> struct scm_creds creds; /* Skb credentials */
> #ifdef CONFIG_SECURITY_NETWORK
> - u32 secid; /* Passed security ID */
> + struct lsmblob lsmblob; /* Passed LSM data */
> #endif
> };
>
> @@ -46,7 +46,7 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl);
> #ifdef CONFIG_SECURITY_NETWORK
> static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
> {
> - security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
> + security_socket_getpeersec_dgram(sock, NULL, &scm->lsmblob);
> }
> #else
> static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
> @@ -97,7 +97,9 @@ static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct sc
> int err;
>
> if (test_bit(SOCK_PASSSEC, &sock->flags)) {
> - err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
> + /* Scaffolding - it has to be element 0 for now */
> + err = security_secid_to_secctx(scm->lsmblob.secid[0],
> + &secdata, &seclen);
>
> if (!err) {
> put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index 82f341e84fae..2a5c868ce135 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -130,15 +130,17 @@ static void ip_cmsg_recv_checksum(struct msghdr *msg, struct sk_buff *skb,
>
> static void ip_cmsg_recv_security(struct msghdr *msg, struct sk_buff *skb)
> {
> + struct lsmblob lb;
> char *secdata;
> - u32 seclen, secid;
> + u32 seclen;
> int err;
>
> - err = security_socket_getpeersec_dgram(NULL, skb, &secid);
> + err = security_socket_getpeersec_dgram(NULL, skb, &lb);
> if (err)
> return;
>
> - err = security_secid_to_secctx(secid, &secdata, &seclen);
> + /* Scaffolding - it has to be element 0 */
> + err = security_secid_to_secctx(lb.secid[0], &secdata, &seclen);
> if (err)
> return;
>
> diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
> index ddb838a1b74c..c50a004a1389 100644
> --- a/net/unix/af_unix.c
> +++ b/net/unix/af_unix.c
> @@ -143,17 +143,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
> #ifdef CONFIG_SECURITY_NETWORK
> static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
> {
> - UNIXCB(skb).secid = scm->secid;
> + UNIXCB(skb).lsmblob = scm->lsmblob;
> }
>
> static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
> {
> - scm->secid = UNIXCB(skb).secid;
> + scm->lsmblob = UNIXCB(skb).lsmblob;
> }
>
> static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
> {
> - return (scm->secid == UNIXCB(skb).secid);
> + return lsmblob_equal(&scm->lsmblob, &(UNIXCB(skb).lsmblob));
> }
> #else
> static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
> diff --git a/security/security.c b/security/security.c
> index f9c8e1926a0b..4e1eb2a54064 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2120,10 +2120,22 @@ int security_socket_getpeersec_stream(struct socket *sock, char __user *optval,
> optval, optlen, len);
> }
>
> -int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
> +int security_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb,
> + struct lsmblob *blob)
> {
> - return call_int_hook(socket_getpeersec_dgram, -ENOPROTOOPT, sock,
> - skb, secid);
> + struct security_hook_list *hp;
> + int rc = -ENOPROTOOPT;
> +
> + hlist_for_each_entry(hp, &security_hook_heads.socket_getpeersec_dgram,
> + list) {
> + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> + continue;
> + rc = hp->hook.socket_getpeersec_dgram(sock, skb,
> + &blob->secid[hp->lsmid->slot]);
> + if (rc != 0)
> + break;
> + }
> + return rc;
> }
> EXPORT_SYMBOL(security_socket_getpeersec_dgram);
>
>
^ permalink raw reply
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