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 <[EMAIL PROTECTED]>
---
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);
--
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