From: valis
stable inclusion
from stable-v5.10.192
commit a8d478200b104ff356f51e1f63499fe46ba8c9b8
category: bugfix
issue: #I7ZATX
CVE: CVE-2023-4207
Signed-off-by: wanxiaoqing
---------------------------------------
[ Upstream commit 76e42ae831991c828cffa8c37736ebfb831ad5ec ]
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
Reported-by: Bing-Jhong Billy Jheng
Signed-off-by: valis
Signed-off-by: Jamal Hadi Salim
Reviewed-by: Victor Nogueira
Reviewed-by: Pedro Tammela
Reviewed-by: M A Ramdhan
Link: https://lore.kernel.org/r/20230729123202.72406-3-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski
Signed-off-by: Sasha Levin
Signed-off-by: wanxiaoqing
---
net/sched/cls_fw.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 41f0898a5a56..08c41f1976c4 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -266,7 +266,6 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
return -ENOBUFS;
fnew->id = f->id;
- fnew->res = f->res;
fnew->ifindex = f->ifindex;
fnew->tp = f->tp;
--
2.25.1
