From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f69.google.com (mail-ot1-f69.google.com [209.85.210.69]) (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 AF8C31F936 for ; Fri, 7 Aug 2026 00:00:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786060838; cv=none; b=WVs+h2mPVnpZ6JRnEBRg+2ff55iQYSHfyb77qPhAbmIil2yDH6rHbtuc5LyNJDnHWALblg1GEaLBYU4LVvpwFmEvW76Y7WABbmcH50DTxtkU91NUT/ihOgUpyM7kCrQqRuIkY0biuER2ZkZ3VxLSghDCz7ZdhKft366GXBPXwPo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786060838; c=relaxed/simple; bh=RWcunV0LMVXicwnvnw7+9o6tgBHwsUqauE+s+07UtMw=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=Qfa22qjhz3kb9qqPEqOy2OT7TvjAjhPncrqK+J5hS4b7kxeS1MMFAiJi1KT5kZcnJpGNZkOLkHZDTFU2ByNVfGgI4/AA5Q3w1ymZnr3OmdXYRClLz+IMYWNTdCAYSekhrxjpWc4Z5Nws8sGu7titg56HUFn6sWsMolnYMRA0xDA= 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=209.85.210.69 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-f69.google.com with SMTP id 46e09a7af769-7e9e2db9914so1862540a34.1 for ; Thu, 06 Aug 2026 17:00:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786060835; x=1786665635; h=content-type:to:from:subject:message-id:in-reply-to:date :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=/n9KGsHRCQsz8PbCYvcSu3nHH4IJAyft64FVOKi4SDU=; b=JOXInHg9rdrZd+C6WrtahANzDe07lHDDtpQWRlzNi/xa5vMa8BE5dQneh37t/ZxKBf iX5V8TCOE/VV6m7pyF+F6qr+PsM9jH2QefJRSWI+CvYifxAz7VA8SOe6acisqK0x3Um4 pQK/SsKogCvALPtqXFBaHKkieqth/fBn8veZbbjDpeHcTTuV6vihSUlBckk16cGLdN3A Sd/xsXUwcXUkshP1bFWVnXO5hLe9wxDEFOV7yub7PwYT/sciX4/apmGFeZCoPXq8ttRW Yxnq+629xubbRqEue5Y66rk5mGbt5w66D2VEsaxl70oGl4UgkTBAFAvVgW+fc/urUlAY D6HA== X-Forwarded-Encrypted: i=1; AHgh+Rrlk4xS+QmJwUBB2zDLi8AAFubQxxZKQJtZxzc7VmhUPPid+FbX7hTyfXbWLR2FwXoPzq2miNt+vz1V/C8=@vger.kernel.org X-Gm-Message-State: AOJu0YxI1ZMQgl+6NNo1WkvNddVVVHftXYVK8Dz1cSSu2Pl9u8gJwuYi mltZpdP9K1IG7pd8VpwBBnQo8xpaPVa9eV11+ZtOgDzl+EomL92aQ1oIZAHQ0WX8xVM10OEcGQt xVIFeBk7ebRDOHk8Sc/btsNLFnXTA4szlm9iuWS38rzoH9bmu76OeovGogZc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4dfb:b0:69d:7fdb:3416 with SMTP id 006d021491bc7-6aebcc4bfd4mr5864216eaf.21.1786060835634; Thu, 06 Aug 2026 17:00:35 -0700 (PDT) Date: Thu, 06 Aug 2026 17:00:35 -0700 In-Reply-To: <00000000000063fd99061ba29d87@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a752023.b50370da.49fe0.0015.GAE@google.com> Subject: Re: [syzbot] [nfs?] INFO: task hung in nfsd_nl_version_get_doit From: syzbot To: chuck.lever@oracle.com, dai.ngo@oracle.com, jlayton@kernel.org, kolga@netapp.com, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, neilb@suse.de, syzkaller-bugs@googlegroups.com, tom@talpey.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: fcaeecb8b0cd Merge tag 'probes-fixes-v7.2-rc6' of git://gi.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10403e49580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d69870d5e052935f dashboard link: https://syzkaller.appspot.com/bug?extid=41bc60511c2884783c27 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=135e57b9580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+41bc60511c2884783c27@syzkaller.appspotmail.com INFO: task syz-executor371:5953 blocked for more than 10 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor371 state:D stack:28568 pid:5953 tgid:5952 ppid:5951 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0xccc/0x1bd0 kernel/locking/mutex.c:821 nfsd_nl_version_get_doit+0x18c/0x810 fs/nfsd/nfsctl.c:1889 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x48b/0x4e0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2255 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fae5b4580de RSP: 002b:00007fae5b402168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fae5b4026c0 RCX: 00007fae5b4580de RDX: 0000000000000014 RSI: 00007fae5b4021e0 RDI: 0000000000000004 RBP: 0000000000000027 R08: 00007fae5b4021d4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffd0 R13: 0000000000000000 R14: 00007fff8af2b580 R15: 00007fff8af2b668 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8ebe6200 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ebe6200 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ebe6200 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:6/501: #0: ffff88801bc44140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900037cfd08 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by getty/5370: #0: ffff8880338d00a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor371/5952: #0: ffffffff90b4d5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f070880 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0xd5/0x1a80 fs/nfsd/nfsctl.c:1964 2 locks held by syz-executor371/5953: #0: ffffffff90b4d5a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff8f070880 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x18c/0x810 fs/nfsd/nfsctl.c:1889 1 lock held by modprobe/7138: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7141 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213 Code: 64 00 be 03 00 00 00 5b e9 42 5e 13 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 45 5b 5a 12 <48> 8b 34 24 65 48 8b 15 21 5b 5a 12 a9 00 01 ff 00 74 1b f6 c4 01 RSP: 0018:ffffc90005907130 EFLAGS: 00000202 RAX: 0000000080000000 RBX: ffff88807253d408 RCX: ffffffff8bb34482 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff88802034ca80 RBP: ffff88807253d450 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000009 R14: dffffc0000000000 R15: ffff88807253d458 FS: 0000000000000000(0000) GS:ffff888123ddd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fed66708440 CR3: 000000002b11f000 CR4: 00000000003526f0 Call Trace: mas_validate_child_slot lib/maple_tree.c:6784 [inline] mt_validate+0x11b0/0x31e0 lib/maple_tree.c:6951 validate_mm+0xa8/0x4e0 mm/vma.c:652 vms_complete_munmap_vmas+0x83b/0xdd0 mm/vma.c:1364 __mmap_complete mm/vma.c:2617 [inline] __mmap_region+0xb42/0x2db0 mm/vma.c:2783 mmap_region+0x35d/0x620 mm/vma.c:2860 do_mmap+0xc63/0x12f0 mm/mmap.c:560 vm_mmap_pgoff+0x29e/0x470 mm/util.c:581 ksys_mmap_pgoff+0x3cb/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fed669ea242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007ffee569ce78 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fed666f6000 RCX: 00007fed669ea242 RDX: 0000000000000005 RSI: 0000000000008000 RDI: 00007fed666f6000 RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000003000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffee569cec8 R13: 00007fed669bf580 R14: 00007ffee569d2f0 R15: 00000fffdcad39d2 --- If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing.