From a3cac7e26bbd944cc8bfc96c81d6784fbde594ec Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 7 Apr 2018 13:42:38 -0700 Subject: net: fix rtnh_ok() 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 Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/nexthop.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/net') diff --git a/include/net/nexthop.h b/include/net/nexthop.h index 3334dbfa5aa4..7fc78663ec9d 100644 --- 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; } -- cgit v1.2.3