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authorvalis <sec@valis.email>2023-07-29 08:32:01 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-09-23 10:48:17 +0200
commit4f38dc8496d1991e2c055a0068dd98fb48affcc6 (patch)
treece4691b75fdda05917e1fcbce3bb995308cea872
parent55e55d7fa5356eea32939617d72f68e5c8b34702 (diff)
net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free
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@starlabs.sg> Signed-off-by: valis <sec@valis.email> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Reviewed-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: M A Ramdhan <ramdhan@starlabs.sg> Link: https://lore.kernel.org/r/20230729123202.72406-3-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ 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@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--net/sched/cls_fw.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 5284a473c697..f15089c24a32 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -277,7 +277,6 @@ static int fw_change(struct net *net, struct sk_buff *in_skb,
return -ENOBUFS;
fnew->id = f->id;
- fnew->res = f->res;
#ifdef CONFIG_NET_CLS_IND
fnew->ifindex = f->ifindex;
#endif /* CONFIG_NET_CLS_IND */