path: root/mm
diff options
authorEric Paris <eparis@redhat.com>2007-12-04 23:45:31 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-12-05 09:21:21 -0800
commitecaf18c15aac8bb9bed7b7aa0e382fe252e275d5 (patch)
treecefce88c3d253992f939c2f8a1b66b8932272cbb /mm
parentSLUB's ksize() fails for size > 2048 (diff)
VM/Security: add security hook to do_brk
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>
Diffstat (limited to 'mm')
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index facc1a75bd4f..acfc13f23ca0 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -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);