path: root/mm
diff options
authorEric Paris <eparis@redhat.com>2007-12-04 11:06:55 -0500
committerJames Morris <jmorris@namei.org>2007-12-06 00:25:30 +1100
commit5a211a5deabcafdc764817d5b4510c767d317ddc (patch)
treed330ce692f43c1b02c84ff81284e6191d567e02f /mm
parentSecurity: round mmap hint address above mmap_min_addr (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 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> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'mm')
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index f4cfc6ac08db..15678aa6ec73 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);