Techwizz/kernel-fxtec-pro1x
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

VM/Security: add security hook to do_brk

Browse source 
Given a specifically crafted binary do_brk() can be used to get low pages
available in userspace virtual 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>
Acked-by: Alan Cox <alan@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Paris 2007-12-04 23:45:31 -08:00 committed by Linus Torvalds
parent 294a80a8ed
commit ecaf18c15a
1 changed files with 4 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
mm/mmap.c
View file

@ -1934,6 +1934,10 @@ 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);