From ee53b42fd8b0b0cdb857d0f5bf7467e22a3457d9 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Wed, 11 Apr 2018 11:43:11 +0200 Subject: [PATCH] iproute: Abort if nexthop cannot be parsed Attempt to add a multipath route where a nexthop definition refers to a non-existent device causes 'ip' to crash and burn due to stack buffer overflow: # ip -6 route add fd00::1/64 nexthop dev fake1 Cannot find device "fake1" Cannot find device "fake1" Cannot find device "fake1" ... Segmentation fault (core dumped) Don't ignore errors from the helper routine that parses the nexthop definition, and abort immediately if parsing fails. Signed-off-by: Jakub Sitnicki --- ip/iproute.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ip/iproute.c b/ip/iproute.c index 1d8fd815..44351bc5 100644 --- a/ip/iproute.c +++ b/ip/iproute.c @@ -1038,7 +1038,10 @@ static int parse_nexthops(struct nlmsghdr *n, struct rtmsg *r, memset(rtnh, 0, sizeof(*rtnh)); rtnh->rtnh_len = sizeof(*rtnh); rta->rta_len += rtnh->rtnh_len; - parse_one_nh(n, r, rta, rtnh, &argc, &argv); + if (parse_one_nh(n, r, rta, rtnh, &argc, &argv)) { + fprintf(stderr, "Error: cannot parse nexthop\n"); + exit(-1); + } rtnh = RTNH_NEXT(rtnh); }