From: valis sec@valis.email
[ Upstream commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/cls_route.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c index d0c53724d3e86..1e20bbd687f1d 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;