From: Masami Hiramatsu <mhiramat@kernel.org>
To: Matthew Garrett <matthewgarrett@google.com>
Cc: jmorris@namei.org, linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, dhowells@redhat.com,
Alexei Starovoitov <alexei.starovoitov@gmail.com>,
"Naveen N . Rao" <naveen.n.rao@linux.ibm.com>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
davem@davemloft.net, Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [PATCH 22/27] Lock down kprobes
Date: Tue, 26 Mar 2019 21:29:57 +0900 [thread overview]
Message-ID: <20190326212957.f5b518990c14cf21262bfdcc@kernel.org> (raw)
In-Reply-To: <20190325220954.29054-23-matthewgarrett@google.com>
On Mon, 25 Mar 2019 15:09:49 -0700
Matthew Garrett <matthewgarrett@google.com> wrote:
> From: David Howells <dhowells@redhat.com>
>
> Disallow the creation of kprobes when the kernel is locked down by
> preventing their registration. This prevents kprobes from being used to
> access kernel memory, either to make modifications or to steal crypto data.
Hmm, if you enforce signature check of modules, those modules
should be allowed to use kprobes?
I think we should introduce some kind of trust inheritance from
signed (trusted) modules.
Thank you,
>
> Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Matthew Garrett <matthewgarrett@google.com>
> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> Cc: davem@davemloft.net
> Cc: Masami Hiramatsu <mhiramat@kernel.org>
> ---
> kernel/kprobes.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index f4ddfdd2d07e..6f66cca8e2c6 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1552,6 +1552,9 @@ int register_kprobe(struct kprobe *p)
> struct module *probed_mod;
> kprobe_opcode_t *addr;
>
> + if (kernel_is_locked_down("Use of kprobes"))
> + return -EPERM;
> +
> /* Adjust probe address from symbol */
> addr = kprobe_addr(p);
> if (IS_ERR(addr))
> --
> 2.21.0.392.gf8f6787159e-goog
>
--
Masami Hiramatsu <mhiramat@kernel.org>
next prev parent reply other threads:[~2019-03-26 12:30 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-25 22:09 [PULL REQUEST] Lockdown patches for 5.2 Matthew Garrett
2019-03-25 22:09 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-03-26 5:30 ` Matthew Garrett
2019-03-25 22:09 ` [PATCH 02/27] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-03-25 22:09 ` [PATCH 03/27] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 04/27] kexec_load: Disable at runtime if " Matthew Garrett
2019-03-25 22:09 ` [PATCH 05/27] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-03-25 22:09 ` [PATCH 06/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-03-25 22:09 ` [PATCH 07/27] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-03-25 22:09 ` [PATCH 08/27] hibernate: Disable when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 09/27] uswsusp: " Matthew Garrett
2019-03-25 22:09 ` [PATCH 10/27] PCI: Lock down BAR access " Matthew Garrett
2019-03-25 22:09 ` [PATCH 11/27] x86: Lock down IO port " Matthew Garrett
2019-03-25 22:09 ` [PATCH 12/27] x86/msr: Restrict MSR " Matthew Garrett
2019-03-25 23:40 ` Thomas Gleixner
2019-03-25 22:09 ` [PATCH 13/27] ACPI: Limit access to custom_method " Matthew Garrett
2019-03-25 22:09 ` [PATCH 14/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-03-25 22:09 ` [PATCH 15/27] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-03-25 22:09 ` [PATCH 16/27] acpi: Disable APEI error injection " Matthew Garrett
2019-03-25 22:09 ` [PATCH 17/27] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 18/27] Lock down TIOCSSERIAL Matthew Garrett
2019-03-25 22:09 ` [PATCH 19/27] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-03-25 22:09 ` [PATCH 20/27] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-03-25 23:35 ` Steven Rostedt
2019-03-25 22:09 ` [PATCH 21/27] Lock down /proc/kcore Matthew Garrett
2019-03-25 22:09 ` [PATCH 22/27] Lock down kprobes Matthew Garrett
2019-03-26 12:29 ` Masami Hiramatsu [this message]
2019-03-26 17:41 ` Matthew Garrett
2019-03-26 22:47 ` Masami Hiramatsu
2019-03-25 22:09 ` [PATCH 23/27] bpf: Restrict kernel image access functions when the kernel is locked down Matthew Garrett
2019-03-25 23:42 ` Stephen Hemminger
2019-03-25 23:59 ` Stephen Hemminger
2019-03-26 0:00 ` Daniel Borkmann
2019-03-26 13:54 ` Jordan Glover
2019-03-26 0:10 ` Andy Lutomirski
2019-03-26 18:57 ` James Morris
2019-03-26 19:22 ` Andy Lutomirski
2019-03-28 3:15 ` James Morris
2019-03-28 18:07 ` Matthew Garrett
2019-03-28 19:23 ` James Morris
2019-03-28 20:08 ` Matthew Garrett
2019-03-26 20:19 ` Matthew Garrett
2019-03-25 22:09 ` [PATCH 24/27] Lock down perf Matthew Garrett
2019-03-25 22:09 ` [PATCH 25/27] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-03-26 0:31 ` Greg Kroah-Hartman
2019-03-26 0:38 ` Matthew Garrett
2019-03-26 0:43 ` Greg Kroah-Hartman
2019-03-25 22:09 ` [PATCH 26/27] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-03-25 22:09 ` [PATCH 27/27] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-03-26 15:33 ` Mimi Zohar
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