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authorvalis <sec@valis.email>2023-07-29 08:32:02 -0400
committerJakub Kicinski <kuba@kernel.org>2023-07-31 20:10:37 -0700
commitb80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8 (patch)
treef4c5c3a4d75bf88d1e78c5aad27c156498b680a8
parent76e42ae831991c828cffa8c37736ebfb831ad5ec (diff)
downloadkvm-s390-vfio-b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8.tar.gz
net/sched: cls_route: No longer copy tcf_result on update to avoid use-after-free
When route4_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: 1109c00547fc ("net: sched: RCU cls_route") 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/20230729123202.72406-4-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/sched/cls_route.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index d0c53724d3e86b..1e20bbd687f1df 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -513,7 +513,6 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
if (fold) {
f->id = fold->id;
f->iif = fold->iif;
- f->res = fold->res;
f->handle = fold->handle;
f->tp = fold->tp;