diff mbox series

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

Message ID 20210408220129.GA3111136@LEGION
State New
Headers show
Series net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh | expand

Commit Message

Muhammad Usama Anjum April 8, 2021, 10:01 p.m. UTC
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>
---
 net/ipv6/route.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

patchwork-bot+netdevbpf@kernel.org April 8, 2021, 11:50 p.m. UTC | #1
Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Fri, 9 Apr 2021 03:01:29 +0500 you wrote:
> 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>
> 
> [...]

Here is the summary with links:
  - net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
    https://git.kernel.org/netdev/net/c/864db232dc70

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 28801ae80548..a22822bdbf39 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5206,9 +5206,11 @@  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 		 * nexthops have been replaced by first new, the rest should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++;
 	}