From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f78.google.com (mail-oo1-f78.google.com [209.85.161.78]) (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 8F954476077 for ; Fri, 7 Aug 2026 12:01:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.78 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786104129; cv=none; b=Pj8QdIVX6zC0D+hN9B0BFbZ4ZfNMxW9wXivE+zsd+AX4gKsO5IFGIhu/dvzOKnNNMqCSnDsiLaBoZc0lELYp+1KpS10IIcnpTzQE25to8lB0FMD76Ce8Qha3fk0HwLOFePgw5i0eSIv8iMeIuiaWscsunNqJSlD09QgUXbiPOTs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786104129; c=relaxed/simple; bh=VmlN0iLlFuPkddnJF3etyfgUuSMcI9aLdcl2X8O7kYE=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=Mlz7lRp+lo/JwRPYG6UGHy+6oC+61tL4foHtp1+ed1Z58yxJfZ6pMZrLm8J74GDXCgRJvxVTdJJMb7UJeCTXNfOpTSHjUL3NbqDQOfoLeMwXI5FNCesXQAB7OgrmfJjnPsa+a00DaywdfStkD9wYmTYWns81DFK5Eo9pmRiL0yc= 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=209.85.161.78 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-oo1-f78.google.com with SMTP id 006d021491bc7-6ae34317b7eso1365783eaf.1 for ; Fri, 07 Aug 2026 05:01:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786104110; x=1786708910; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=TNHlJOOtYHZV/PWY8v8K5jzZCHd/TxoORitOqwKTAf0=; b=WzVWP37lyhWnpz8c8Q7p1/kcHLIvo1GY9WJfdiZt8NFe8i+K0Eyx+kh1/9susSNi/K 5k9rqlN2izoNWTu7SKUy14z/f0AYLhk5U1vqd87JOGNyvRvZs/+SUNjmRUPASwFWCEXN ZrNbLudS4ywK46CCO0BZFD+quOIHAVD1eWWjHIU9ZdyVUZORyyPPo9RiBODu9hjwVEzE PoYRH08YModyDHe1ho99xfkAXqkgK1htGT7DKv9TyIgKPhXbXQou06PnD3Vqb4dTmSwN wJ2ruDbdXrkRfibaRDqK1eOhdVU93e1u+FIGfcdR1NtQGz8aICNWJ3RV/66OkyGcaZEP harw== X-Forwarded-Encrypted: i=1; AHgh+RqdgA1TsJoYP41wJ+n6Ex3q0hPKD7ZJKJ5YEhnfePWud/Mz3R9CW7b0YdHvrFEpQXp0m8jFr024NeVHN1c=@vger.kernel.org X-Gm-Message-State: AOJu0Yz7iUQsA5aDqryeKoylt487xXEQykwfKOFsW2PSarkfwWHr1y3w QjhIAxlCFCtJ0aEcVdDWUYQy9EY+nhmCxqFsiGtraELDb0V8WemEBi069EJXNwqsGFMnIto/CJO sPw99DE9SfkQwP90n20fYKHjscv486xNjuacw2NQrPFHRcVKI8xhhJKIe/vA= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1f07:b0:6ae:4131:98c6 with SMTP id 006d021491bc7-6ae96bd0a8bmr11874498eaf.2.1786104109996; Fri, 07 Aug 2026 05:01:49 -0700 (PDT) Date: Fri, 07 Aug 2026 05:01:49 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a75c92d.01d0871a.3a0d52.0046.GAE@google.com> Subject: [syzbot] [kernel?] INFO: task hung in copy_ipcs From: syzbot To: anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tglx@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: cc2b5f627e8c Add linux-next specific files for 20260714 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=1355ec9e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=2290ccbf984c524f dashboard link: https://syzkaller.appspot.com/bug?extid=97a62389c5611b0477f3 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b68cc6580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=104d2649580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6836f8efb1da/disk-cc2b5f62.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0109d3477cc7/vmlinux-cc2b5f62.xz kernel image: https://storage.googleapis.com/syzbot-assets/c2e49e350bbf/bzImage-cc2b5f62.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+97a62389c5611b0477f3@syzkaller.appspotmail.com INFO: task syz-executor845:5856 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor845 state:D stack:27496 pid:5856 tgid:5856 ppid:5633 task_flags:0x400140 flags:0x00080802 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7231 __schedule_loop kernel/sched/core.c:7308 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7323 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153 __flush_work+0x9c2/0xd70 kernel/workqueue.c:4431 create_ipc_ns ipc/namespace.c:55 [inline] copy_ipcs+0x19b/0x6c0 ipc/namespace.c:116 create_new_namespaces+0x210/0x6b0 kernel/nsproxy.c:112 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234 ksys_unshare+0x5a7/0x950 kernel/fork.c:3291 __do_sys_unshare kernel/fork.c:3355 [inline] __se_sys_unshare kernel/fork.c:3353 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3353 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcdad6be489 RSP: 002b:00007ffd32b38008 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fcdad6be489 RDX: ffffffffffffffd8 RSI: ffffffffffffffd8 RDI: 0000000028000080 RBP: 0000000000041bab R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 00007ffd32b3801c R13: 431bde82d7b634db R14: 00007fcdad751c40 R15: 0000000000000002 Showing all locks held in the system: locks held by khungtaskd/39: 1, last CPU#0: #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6835 locks held by kworker/0:2/200: 2, on CPU#0: #0: ffff88813fe63938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88813fe63938 ((wq_completion)events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88813fe63938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90004287c60 (free_ipc_work){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90004287c60 (free_ipc_work){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90004287c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 locks held by kworker/u8:16/3068: 2, on CPU#0: #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801aea4138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc9000e8e7c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc9000e8e7c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc9000e8e7c60 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 locks held by getty/5350: 2, on CPU#0: #0: ffff888036a890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044cb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 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+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: 0c 74 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 66 19 00 fb f4 4c d0 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc900001e7e40 EFLAGS: 00000242 RAX: 00000000000e23d3 RBX: ffffffff8199b400 RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8d98ba58 RDI: ffffffff8bcbd080 RBP: ffffc900001e7f10 R08: ffff8880b8733d1b R09: 1ffff110170e67a3 R10: dffffc0000000000 R11: ffffed10170e67a4 R12: 0000000000000000 R13: 1ffff11003c50bb8 R14: 1ffff9200003cfd0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125af2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005636f3bac660 CR3: 000000000e1b0000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:767 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:768 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x2e0/0x540 kernel/sched/idle.c:355 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x157 --- 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 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. 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