From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f70.google.com (mail-ot1-f70.google.com [209.85.210.70]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2004637998C for ; Thu, 14 May 2026 11:12:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.70 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778757176; cv=none; b=q5bDjKUzHZBnHODHvvigzi8LHxJvTtScH4w69e60uu3fFPO6PCxVS4CuPEInzjAThHs8fgYVDSXOzK068y8d7wJA/BGtxYfsn5ztriP/PekQvkj5bCLQR+JGi8/kDRr7MKjjNpheQJOqCd+zE0SlEDGvxf2EJwG/LPDh1pa/jC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778757176; c=relaxed/simple; bh=+sDHD/iGBxRKkZHcXGWeWIL7PEiQP6U78J2edaZYp+M=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=IKqhp9gCfx3foU+20TT8QKdN8QxpcqYz2xkDrkl+mRSL6KXcmqamLCUe/lXXtOTadHsxzzIi15pKXyGcGR1vmVXiVmzKKCtNH4KLLcxa/ni7EgklVOlTn40xTG1TW4TqxXLMX56BzEtws+Vhi9x8A3an7VsJwWLGVRVBKCcbnG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.70 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f70.google.com with SMTP id 46e09a7af769-7e3a5fc58feso10577135a34.0 for ; Thu, 14 May 2026 04:12:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778757172; x=1779361972; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=aMw4ucs2QGt59yoe8RV/EwloNOQTH/0sZcdGmYX7uFg=; b=FeNb4usPfWz8gs+kVRbR1uTu73rUmkcnaaTG7c/IrYh4Uzs0Aisxgalw0wU4gW3o71 mUmEcYPgo4qBH0s4MnJgMIovzdH2bhBR0rn3dIOQTe8jYZzxj3nkjtAqcfxGRT31uFR2 vKRx4ipVeKHMlT2NVlh1m/QT5nGAJ2ZWC1r+QnpFF1FVAtLtG1Lmo+hEiCfCAVGVTFMU XgFKGSSE5me7mwbWj9w5KCBBXakqLI8yMhjLHLhXmU0MyoZd3vHIvQb2y38ZmGa1HJzq 6MJkWRvUUWcp4fEUTiGMhSRFMH63lY8bpX9EoI2hKq3rePgqwBgHVPHPD3w9KJOZz7bi bSrw== X-Gm-Message-State: AOJu0YxTeCaAT6CIZOlLPfSWVRq3Xk34Nf2Jw0umvXgZB+TJETi59iiR 5e8J3OkXmIx9TyqqF+MgcFutUpnXYodCqwenB34eJ69FuoJq7eCFlVoa3uqehSxkIxtRdbvksb4 2lSFarpwQpSxsdE4HC6pdkJDMQMskqJDGyIrwVCZMWuUYHlWtqPchdfOWfl0= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a4a:e915:0:b0:696:1791:add8 with SMTP id 006d021491bc7-69b78e40a62mr4039116eaf.40.1778757171924; Thu, 14 May 2026 04:12:51 -0700 (PDT) Date: Thu, 14 May 2026 04:12:51 -0700 In-Reply-To: <6a00e81a.170a0220.1c0296.0218.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a05ae33.170a0220.196691.0005.GAE@google.com> Subject: Forwarded: [syzbot] test WARN_ON for addrconf on unregistering devices From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [syzbot] test WARN_ON for addrconf on unregistering devices Author: raoxu@uniontech.com #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci From: Xu Rao Subject: [PATCH debug] ipv6: addrconf: warn on autoconf for unregistering devices Add WARN_ON() checks where the proposed fix skips IPv6 autoconf on unregistering devices. This is a diagnostic patch to confirm whether the syzbot reproducer reaches the MTU / UP / CHANGE paths after the netdevice has entered NETREG_UNREGISTERING. Signed-off-by: Xu Rao --- net/ipv6/addrconf.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 5476b6536eb7..72a3b17d30a1 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3666,6 +3666,8 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, break; case NETDEV_CHANGEMTU: + WARN_ON(dev->reg_state == NETREG_UNREGISTERING); + /* if MTU under IPV6_MIN_MTU stop IPv6 on this interface. */ if (dev->mtu < IPV6_MIN_MTU) { addrconf_ifdown(dev, dev != net->loopback_dev); @@ -3691,12 +3693,14 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, fallthrough; case NETDEV_UP: case NETDEV_CHANGE: + WARN_ON(dev->reg_state == NETREG_UNREGISTERING); + if (idev && idev->cnf.disable_ipv6) break; if (dev->priv_flags & IFF_NO_ADDRCONF) { if (event == NETDEV_UP && !IS_ERR_OR_NULL(idev) && dev->flags & IFF_UP && dev->flags & IFF_MULTICAST) ipv6_mc_up(idev); break; } -- 2.50.1