From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B1C66425868 for ; Mon, 20 Jul 2026 15:56:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784562980; cv=none; b=sizI1lYF9+eE329b7y/AyhKQaii548cegad8SX8mvXj+sHIFZgmgiQKWkeqcPJLlqUrypwYtb1wu3jnEJKCVSbKQbF8kCofJi10364CVlZ/rRdjEibWUiV5UXkuqB5h7DLFC8315wi9QTegv/Y8OhyadRuy9ES7B1y1H8fF+xuo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784562980; c=relaxed/simple; bh=1VcPE+pineVXk8g1MR8K5GnhjlUkPFSjpquWbaKZN0c=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=VQzI5q0JzbmvtwIgyboF1SrHiKJ6kxESTkKVh/hNR1rB7cggyfpnvnxcWTVhOe5mhLCcHJ3SANLjYfJEGVzmWpfTaoPfMu9pW9DtU4WPVZ9mUbUatYYHjzDTEePRte8RGkCOo7/xUQviofuQFlS3QMplssL8voffKBN3vbaPEWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JF7drbrb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JF7drbrb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCE4C1F00A3A; Mon, 20 Jul 2026 15:56:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784562978; bh=Gu/S3iCq6pJElOiIgJomNtHF52/tpLXQsBYIw7Z15T0=; h=Subject:To:Cc:From:Date; b=JF7drbrbYix4ui0Ta9waQ2X1Delpn5QQbMbsYa1gHEFbz3zpqWEII1MuFcQnWup2B 8pY6DHXsutZExL04kz/F5aT2ZBuZ7nj/O3xTlH/gjZHd9emG66h0w4F7rtnLnfprza vEmdJ+uCKqwMx42NcHDRtSSLc2Tr/OkwjMlEtH24= Subject: FAILED: patch "[PATCH] net/sched: act_ct: preserve tc_skb_cb across defragmentation" failed to apply to 5.15-stable tree To: xizh2024@lzu.edu.cn,bird@lzu.edu.cn,kuba@kernel.org,n05ec@lzu.edu.cn,tomapufckgml@gmail.com,yifanwucs@gmail.com,yuantan098@gmail.com Cc: From: Date: Mon, 20 Jul 2026 17:52:19 +0200 Message-ID: <2026072019-provoking-acutely-210b@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 9092e15defbe6c7bc241c306093ca9d358a578e7 # git commit -s git send-email --to '' --in-reply-to '2026072019-provoking-acutely-210b@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9092e15defbe6c7bc241c306093ca9d358a578e7 Mon Sep 17 00:00:00 2001 From: Zihan Xi Date: Sun, 14 Jun 2026 01:42:39 +0800 Subject: [PATCH] net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled. Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments(). Fixes: ec624fe740b4 ("net/sched: Extend qdisc control block with tc control block") Cc: stable@vger.kernel.org Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Signed-off-by: Zihan Xi Signed-off-by: Ren Wei Link: https://patch.msgid.link/510c51217fd7aaf29c6dc298bab8d643fe229b1c.1781358692.git.xizh2024@lzu.edu.cn Signed-off-by: Jakub Kicinski diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c index 6158e13c98d3..d47a82f9ac6c 100644 --- a/net/sched/act_ct.c +++ b/net/sched/act_ct.c @@ -844,11 +844,11 @@ static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb, u8 family, u16 zone, bool *defrag) { enum ip_conntrack_info ctinfo; + struct tc_skb_cb cb; struct nf_conn *ct; int err = 0; bool frag; u8 proto; - u16 mru; /* Previously seen (loopback)? Ignore. */ ct = nf_ct_get(skb, &ctinfo); @@ -862,12 +862,13 @@ static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb, if (err || !frag) return err; - err = nf_ct_handle_fragments(net, skb, zone, family, &proto, &mru); + cb = *tc_skb_cb(skb); + err = nf_ct_handle_fragments(net, skb, zone, family, &proto, &cb.mru); if (err) return err; *defrag = true; - tc_skb_cb(skb)->mru = mru; + *tc_skb_cb(skb) = cb; return 0; }