4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <v...@zeniv.linux.org.uk>
commit f35c1e0671728d1c9abc405d05ef548b5fcb2fc4 upstream.
It's -EFAULT, not -1 (and contrary to the comment in there,
__strnlen_user() can return 0 - on faults).
Acked-by: Richard Kuo <r...@codeaurora.org>
Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/hexagon/include/asm/uaccess.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/hexagon/include/asm/uaccess.h
+++ b/arch/hexagon/include/asm/uaccess.h
@@ -103,7 +103,8 @@ static inline long hexagon_strncpy_from_
{
long res = __strnlen_user(src, n);
- /* return from strnlen can't be zero -- that would be rubbish. */
+ if (unlikely(!res))
+ return -EFAULT;
if (res > n) {
copy_from_user(dst, src, n);
