From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta0.migadu.com (out-186.mta0.migadu.com [91.218.175.186]) (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 5DC753BB57 for ; Thu, 16 Apr 2026 07:50:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776325814; cv=none; b=DV5ziJSj/LrfAsK3lVsbMrA6UDIR0wO0tFrHoCeIntm9KgbNK2Ieen7QHvFpnW2mGpKQB5nYW5CVOA38ojs25VXTtR84qhxBb1nn0m8vM4hqyfWCmrGxJVoN3y8c958h/fB8EKPakNHZfcjzpfaJPjwbFZPoAE86uvRSffjWC1o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776325814; c=relaxed/simple; bh=KxuNWQ2a3a9rgfOr9Cf2/P6mQx3czM9m0lYSOzgROec=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Z/efCCYaomnIBj6NrPygO4c0t5VqVnjZMXXSvdXd6WYl59fcYEcTy5z1nI0uWhIt6mVfXw+9RhsFzvIwJG7/jbKDJyWr8Ix2eSxOKdjDKNR8YW8M7VZ1V907OldFOOOZ1GFITM2ELkLfl+MB1qsfIupOPrI7H6hDetT/W+b7QYc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=xV8yrVIJ; arc=none smtp.client-ip=91.218.175.186 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="xV8yrVIJ" Message-ID: <0e579779-f38b-4db3-936b-5d7add12d15e@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776325810; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=11cyg0mvKQwNL/9Dn8fT/UbJkY9yFbzdNgRtigL8718=; b=xV8yrVIJm3m5Eoss2vL0r2ithRXeQ2KtK434zYXzyj821InVMuKPvhtIAiiq97KeX74jy2 aQ5sO2zvfEmCMT38NiYa7kearyrZSbsBqK8OLrW8edfRIbMwqBUVWpSEyNFXOVUaKCgAw1 lwC+YEu1sL7qITn6zMdDMvpvsr7NNa8= Date: Thu, 16 Apr 2026 15:49:58 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [syzbot ci] Re: net: tunnel: fix stale transport header after GRE/TEB decap To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, pshelar@nicira.com, syzbot@syzkaller.appspotmail.com, tom@herbertland.com Cc: syzkaller-bugs@googlegroups.com References: <69e08a0a.a70a0220.259bc5.0019.GAE@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Jiayuan Chen In-Reply-To: <69e08a0a.a70a0220.259bc5.0019.GAE@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 4/16/26 3:04 PM, syzbot ci wrote: > syzbot ci has tested the following series > > [v1] net: tunnel: fix stale transport header after GRE/TEB decap > https://lore.kernel.org/all/20260416034610.8873-1-jiayuan.chen@linux.dev > * [PATCH net v1 1/2] net: tunnel: fix stale transport header after GRE/TEB decap > * [PATCH net-next v1 2/2] net: add DEBUG_NET_WARN_ON_ONCE for negative transport offset > > and found the following issue: > WARNING in udpv6_err > > Full report is available here: > https://ci.syzbot.org/series/3886f2f1-a6d5-4c5c-8dc8-bc1cec577567 > > *** > > WARNING in udpv6_err > > tree: net > URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git > base: 1f5ffc672165ff851063a5fd044b727ab2517ae3 > arch: amd64 > compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 > config: https://ci.syzbot.org/builds/06cf41a2-60fe-4f9b-8f68-57eb6d1e48cc/config > > ------------[ cut here ]------------ > off < 0 > WARNING: ./include/linux/skbuff.h:3239 at udpv6_err+0x1521/0x16d0, CPU#0: kworker/u9:2/51 > Modules linked in: icmpv6_rcv   pskb_pull ==> skb_transport_offset() = -8   icmpv6_notify     udpv6_err       __udp6_lib_err_encap(skb) ==> WARNING