From 212a7aaded26d928452b1d4bc1c756fb3bfbf782 Mon Sep 17 00:00:00 2001 From: valis Date: Sat, 29 Jul 2023 08:32:02 -0400 Subject: [PATCH] UPSTREAM: net/sched: cls_route: No longer copy tcf_result on update to avoid use-after-free [ 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. Bug: 296347075 Fixes: 1109c00547fc ("net: sched: RCU cls_route") 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/20230729123202.72406-4-jhs@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin (cherry picked from commit d4d3b53a4c66004e8e864fea744b3a2b86a73b62) Signed-off-by: Lee Jones Change-Id: Iefbd201b92847ec1349f92c107d7ef5aec3fb359 --- 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 b775e681cb56e..1ad4b3e60eb3b 100644 --- a/net/sched/cls_route.c +++ b/net/sched/cls_route.c @@ -511,7 +511,6 @@ 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;