From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A0DD415AE3 for ; Wed, 9 Aug 2023 10:48:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21DE2C433C8; Wed, 9 Aug 2023 10:48:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691578088; bh=S3gB5s55n2AR9Sg5YLg2vDI0OAK78jtsruqrxYgQAQk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wJHiVveQOshG/3wHIaS75FMLkpW4Y7cVopR7ilO2dme/inBSJptAMpDqaOq67N3kZ LGiJZkoPgJNZY3UChWP8Vh6n0AOmSTLCps5aeDiU9oYJViHvsYtZiItA1YDC2X8Bdh cUbRZNyN4bOdhuDfdOMvCskJBghckxyIufz2zcp8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, valis , Bing-Jhong Billy Jheng , Jamal Hadi Salim , Victor Nogueira , Pedro Tammela , M A Ramdhan , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.4 072/165] net/sched: cls_fw: No longer copy tcf_result on update to avoid use-after-free Date: Wed, 9 Aug 2023 12:40:03 +0200 Message-ID: <20230809103645.162014073@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103642.720851262@linuxfoundation.org> References: <20230809103642.720851262@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: valis [ 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 --- 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 8641f80593179..c49d6af0e0480 100644 --- a/net/sched/cls_fw.c +++ b/net/sched/cls_fw.c @@ -267,7 +267,6 @@ 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; -- 2.40.1