From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f207.google.com (mail-il1-f207.google.com [209.85.166.207]) (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 D5CAC2459FF for ; Mon, 23 Jun 2025 12:36:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750682189; cv=none; b=G73ywAiNT73vl/KQx9bHXRZXWijg+6KgvyCzDTzi8Z71hb7Bdmftc0q9V8uVBX7fA0b+oFyz68/Muxm+7IUyZJmQSbQJRs55GGHW8OeFAJQ8u8S2moDqxQCmUpHf97VjyLkf78FBldMoWa9MMALaUz0Fk1LMpFwIik9Bhb2Je5Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750682189; c=relaxed/simple; bh=I94hyQyD/qKXs1D3uD4NdBsilxac862akXLbKXvNFLk=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=IRnR+TYu9qj9ONemGquu0VKIaINHLYHp5TkMfDetG8r08NapwpQcd8B33NC0wWgAF+iZlcNugr9NbiVZoX/XxLEknzVugB6rGQsLmDFUpjohIjy3Kvb09+wVNDbjONzCzayVhcFuxF7Q32nP3V//qSG/oQbZXNGYsi1Anp/AJe4= 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=209.85.166.207 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-il1-f207.google.com with SMTP id e9e14a558f8ab-3ddba1b53e8so41781565ab.1 for ; Mon, 23 Jun 2025 05:36:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750682187; x=1751286987; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=lckP2yk9BWndyCy1qwAHEv9eAD3uVxRbyKNvTUYHF1A=; b=A6NeUmehDMGu+pK4JFmX/bX2EZpNPdANJZHbue5QJO9wEfuoTHe415sMWJuepOXypT TptSztUnZFH5xUqaKaAkAHsN1ll8EDsk5lxFc3y+1gcBoyCQbUS+rm6ezxiuJkNTv5R9 TlzKJwEGhYOobuM29Kn9Va6LK2owkQcs7nnrDR0Nr4aBEMzMIvBtSdHT6VoveivkP0HK bjzJTWCvlrq9uZ2lSg0a80CFCTBmwnKV5xu8+3dvvxByjsrXKlC4YdAmnDPIhKLAA3ba quldGiZPEzuPjS8gsnjHiK5/6RI0+Ss87AqaMJnoXRj1src12cowCiNeSA8hjCLM1Hgt Gkcg== X-Forwarded-Encrypted: i=1; AJvYcCXrm2Wj4d4gfFvJFSKevFtAb5+Xpl0zvEeUHm+b1CGwbvk5ND5402WlcPXRjuJCVZchfs1Vkwo=@vger.kernel.org X-Gm-Message-State: AOJu0YzpLsdaB86N6Vjuu7UE1+RiP+LNsD79nglFID51X8fiUBUBMO7d fwFj7L804tdskPj8v5A5qddPs5ox/5NPw2DprofUm27Ucpa3+MRGffyMoVxqdwa/YJBVdFJ0G/O mUToIdofEqh2G8bsLWQ04G4+FjlM++9XZQqFIwt74d9/VI659g5XFVIfN6Fs= X-Google-Smtp-Source: AGHT+IHYd0s5sUElagbhJyUuV1IzLCihPj/5gGq7jGwxTdrS1pjcrM3DCWD1UjunEB0OgthYNtBFU54G4rZXb/yR2BjHMEjEJ15U Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:3b83:b0:3dd:c4ed:39c0 with SMTP id e9e14a558f8ab-3de38c159a7mr159435025ab.1.1750682186978; Mon, 23 Jun 2025 05:36:26 -0700 (PDT) Date: Mon, 23 Jun 2025 05:36:26 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68594a4a.a00a0220.34b642.0009.GAE@google.com> Subject: [syzbot] [net?] WARNING in qdisc_tree_reduce_backlog From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, jhs@mojatatu.com, jiri@resnulli.us, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, xiyou.wangcong@gmail.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 739a6c93cc75 Merge tag 'nfsd-6.16-1' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15302dd4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=4130f4d8a06c3e71 dashboard link: https://syzkaller.appspot.com/bug?extid=0a5453a1b326f68c4302 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-739a6c93.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/e3c3204516e7/vmlinux-739a6c93.xz kernel image: https://storage.googleapis.com/syzbot-assets/4396a9588ad1/bzImage-739a6c93.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+0a5453a1b326f68c4302@syzkaller.appspotmail.com ------------[ cut here ]------------ WARNING: CPU: 1 PID: 14934 at net/sched/sch_api.c:809 qdisc_tree_reduce_backlog+0x2d1/0x5a0 net/sched/sch_api.c:809 Modules linked in: CPU: 1 UID: 0 PID: 14934 Comm: syz.0.2492 Not tainted 6.16.0-rc2-syzkaller-00318-g739a6c93cc75 #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:qdisc_tree_reduce_backlog+0x2d1/0x5a0 net/sched/sch_api.c:809 Code: fc 3e f8 45 85 f6 75 25 e8 6c 01 3f f8 44 8b 7c 24 14 31 ff 45 09 e7 44 89 fe e8 9a fc 3e f8 45 85 ff 75 6d e8 50 01 3f f8 90 <0f> 0b 90 e8 47 01 3f f8 8b 34 24 4c 89 ef e8 0c fa ff ff 49 89 c7 RSP: 0018:ffffc90006ebf290 EFLAGS: 00010293 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff897d1af6 RDX: ffff88802dc5c880 RSI: ffffffff897d1b00 RDI: 0000000000000005 RBP: 00000000000affe0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 R13: ffff888037efe000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f66590096c0(0000) GS:ffff8880d6853000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 00000000473da000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000800000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: qdisc_purge_queue include/net/sch_generic.h:982 [inline] qdisc_replace include/net/sch_generic.h:1232 [inline] tbf_graft+0x1dd/0x800 net/sched/sch_tbf.c:570 qdisc_graft+0x341/0x17c0 net/sched/sch_api.c:1210 __tc_modify_qdisc net/sched/sch_api.c:1766 [inline] tc_modify_qdisc+0xf48/0x2130 net/sched/sch_api.c:1822 rtnetlink_rcv_msg+0x3c6/0xe90 net/core/rtnetlink.c:6953 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x53a/0x7f0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2566 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620 __sys_sendmsg+0x16d/0x220 net/socket.c:2652 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f665818e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6659009038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f66583b6160 RCX: 00007f665818e929 RDX: 0000000000004000 RSI: 0000200000000280 RDI: 0000000000000005 RBP: 00007f6658210b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f66583b6160 R15: 00007ffeeab8d708 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup