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authorMuhammad Usama Anjum <musamaanjum@gmail.com>2021-04-09 01:01:29 +0300
committerDavid S. Miller <davem@davemloft.net>2021-04-09 02:41:46 +0300
commit864db232dc7036aa2de19749c3d5be0143b24f8f (patch)
treedc7d062aa31dd41d2dde3653442a412fec116fef
parent2d1b50abf8d4964b14705bfec253be6e80c22099 (diff)
downloadlinux-864db232dc7036aa2de19749c3d5be0143b24f8f.tar.xz
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>
-rw-r--r--net/ipv6/route.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 1056b0229ffd..373d48073106 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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* nexthops have been replaced by first new, the rest should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.
*/
- cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
- NLM_F_REPLACE);
- cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
+ 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++;
}