This is a note to let you know that I've just added the patch titled
net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-ipv6-check-for-validity-before-dereferencing-cfg-fc_nlinfo.nlh.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 864db232dc7036aa2de19749c3d5be0143b24f8f Mon Sep 17 00:00:00 2001
From: Muhammad Usama Anjum <musamaanjum@xxxxxxxxx>
Date: Fri, 9 Apr 2021 03:01:29 +0500
Subject: net: ipv6: check for validity before dereferencing cfg->fc_nlinfo.nlh
From: Muhammad Usama Anjum <musamaanjum@xxxxxxxxx>
commit 864db232dc7036aa2de19749c3d5be0143b24f8f upstream.
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@xxxxxxxxxxxxxxx>
Addresses-Coverity: ("NULL pointer dereference")
Signed-off-by: Muhammad Usama Anjum <musamaanjum@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/route.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5183,9 +5183,11 @@ static int ip6_route_multipath_add(struc
* nexthops have been replaced by first new, the rest should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++;
}
Patches currently in stable-queue which might be from musamaanjum@xxxxxxxxx are
queue-5.4/net-ipv6-check-for-validity-before-dereferencing-cfg-fc_nlinfo.nlh.patch
