* [PATCH] VM/Security: add security hook to do_brk
@ 2007-12-04 16:06 Eric Paris
2007-12-04 16:43 ` Alan Cox
0 siblings, 1 reply; 3+ messages in thread
From: Eric Paris @ 2007-12-04 16:06 UTC (permalink / raw)
To: linux-kernel
Cc: jmorris, alan, chrisw, akpm, linux-security-module, solar,
wtarreau
Given a specifically crafted binary do_brk() can be used to get low
pages available in userspace virtually memory and can thus be used to
circumvent the mmap_min_addr low memory protection. Add security checks
in do_brk().
Signed-off-by: Eric Paris <eparis@redhat.com>
---
mm/mmap.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/mm/mmap.c b/mm/mmap.c
index f4cfc6a..15678aa 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1941,6 +1941,10 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
if (is_hugepage_only_range(mm, addr, len))
return -EINVAL;
+ error = security_file_mmap(0, 0, 0, 0, addr, 1);
+ if (error)
+ return error;
+
flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
error = arch_mmap_check(addr, len, flags);
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] VM/Security: add security hook to do_brk
2007-12-04 16:06 [PATCH] VM/Security: add security hook to do_brk Eric Paris
@ 2007-12-04 16:43 ` Alan Cox
2007-12-05 12:15 ` James Morris
0 siblings, 1 reply; 3+ messages in thread
From: Alan Cox @ 2007-12-04 16:43 UTC (permalink / raw)
To: Eric Paris
Cc: linux-kernel, jmorris, alan, chrisw, akpm, linux-security-module,
solar, wtarreau
On Tue, Dec 04, 2007 at 11:06:55AM -0500, Eric Paris wrote:
> Given a specifically crafted binary do_brk() can be used to get low
> pages available in userspace virtually memory and can thus be used to
> circumvent the mmap_min_addr low memory protection. Add security checks
> in do_brk().
>
> Signed-off-by: Eric Paris <eparis@redhat.com>
ACK
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] VM/Security: add security hook to do_brk
2007-12-04 16:43 ` Alan Cox
@ 2007-12-05 12:15 ` James Morris
0 siblings, 0 replies; 3+ messages in thread
From: James Morris @ 2007-12-05 12:15 UTC (permalink / raw)
To: Alan Cox
Cc: Eric Paris, linux-kernel, chrisw, akpm, linux-security-module,
solar, wtarreau
On Tue, 4 Dec 2007, Alan Cox wrote:
> On Tue, Dec 04, 2007 at 11:06:55AM -0500, Eric Paris wrote:
> > Given a specifically crafted binary do_brk() can be used to get low
> > pages available in userspace virtually memory and can thus be used to
> > circumvent the mmap_min_addr low memory protection. Add security checks
> > in do_brk().
> >
> > Signed-off-by: Eric Paris <eparis@redhat.com>
>
> ACK
Applied to
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6.git#for-akpm
--
James Morris
<jmorris@namei.org>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2007-12-04 16:06 [PATCH] VM/Security: add security hook to do_brk Eric Paris
2007-12-04 16:43 ` Alan Cox
2007-12-05 12:15 ` James Morris
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