3.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet edumazet@google.com
commit b1993a2de12c9e75c35729e2ffbc3a92d50c0d31 upstream.
syzbot reported :
BUG: KMSAN: uninit-value in rtnh_ok include/net/nexthop.h:11 [inline] BUG: KMSAN: uninit-value in fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline] BUG: KMSAN: uninit-value in fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091
@remaining is an integer, coming from user space. If it is negative we want rtnh_ok() to return false.
Fixes: 4e902c57417c ("[IPv4]: FIB configuration using struct fib_config") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- include/net/nexthop.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/net/nexthop.h +++ b/include/net/nexthop.h @@ -6,7 +6,7 @@
static inline int rtnh_ok(const struct rtnexthop *rtnh, int remaining) { - return remaining >= sizeof(*rtnh) && + return remaining >= (int)sizeof(*rtnh) && rtnh->rtnh_len >= sizeof(*rtnh) && rtnh->rtnh_len <= remaining; }