This is a note to let you know that I've just added the patch titled
net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free
to the 4.14-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-sched-cls_fw-no-longer-copy-tcf_result-on-update-to-avoid-use-after-free.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 76e42ae831991c828cffa8c37736ebfb831ad5ec Mon Sep 17 00:00:00 2001
From: valis <sec@valis.email>
Date: Sat, 29 Jul 2023 08:32:01 -0400
Subject: net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free
From: valis <sec@valis.email>
commit 76e42ae831991c828cffa8c37736ebfb831ad5ec upstream.
When fw_change() is called on an existing filter, the whole
tcf_result struct is always copied into the new instance of the filter.
This causes a problem when updating a filter bound to a class,
as tcf_unbind_filter() is always called on the old instance in the
success path, decreasing filter_cnt of the still referenced class
and allowing it to be deleted, leading to a use-after-free.
Fix this by no longer copying the tcf_result struct from the old filter.
Fixes: e35a8ee5993b ("net: sched: fw use RCU")
Reported-by: valis <sec@valis.email>
Reported-by: Bing-Jhong Billy Jheng <billy@xxxxxxxxxxx>
Signed-off-by: valis <sec@valis.email>
Signed-off-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Reviewed-by: Victor Nogueira <victor@xxxxxxxxxxxx>
Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
Reviewed-by: M A Ramdhan <ramdhan@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230729123202.72406-3-jhs@xxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
[ Fixed small conflict as 'fnew->ifindex' assignment is not protected by
CONFIG_NET_CLS_IND on upstream since a51486266c3 ]
Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/cls_fw.c | 1 -
1 file changed, 1 deletion(-)
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -281,7 +281,6 @@ static int fw_change(struct net *net, st
return -ENOBUFS;
fnew->id = f->id;
- fnew->res = f->res;
#ifdef CONFIG_NET_CLS_IND
fnew->ifindex = f->ifindex;
#endif /* CONFIG_NET_CLS_IND */
Patches currently in stable-queue which might be from sec@valis.email are
queue-4.14/net-sched-cls_fw-no-longer-copy-tcf_result-on-update-to-avoid-use-after-free.patch
queue-4.14/net-sched-sch_qfq-fix-uaf-in-qfq_dequeue.patch
