Commit 864db232 authored Apr 09, 2021 by Muhammad Usama Anjum Committed by David S. Miller Apr 08, 2021

net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh



nlh is being checked for validtity two times when it is dereferenced in
this function. Check for validity again when updating the flags through
nlh pointer to make the dereferencing safe.

CC: <stable@vger.kernel.org>
Addresses-Coverity: ("NULL pointer dereference")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2d1b50ab

net/ipv6/route.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -5209,9 +5209,11 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
		* nexthops have been replaced by first new, the rest should
		* be added to it.
		*/
		if (cfg->fc_nlinfo.nlh) {
		cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL \|
		NLM_F_REPLACE);
		cfg->fc_nlinfo.nlh->nlmsg_flags \|= NLM_F_CREATE;
		}
		nhn++;
		}