From b1993a2de12c9e75c35729e2ffbc3a92d50c0d31 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 7 Apr 2018 13:42:38 -0700 Subject: [PATCH] net: fix rtnh_ok() 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 --- include/net/nexthop.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/net/nexthop.h b/include/net/nexthop.h index 36bb794f5cd6..902ff382a6dc 100644 --- a/include/net/nexthop.h +++ b/include/net/nexthop.h @@ -7,7 +7,7 @@ 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; } -- 2.30.2