From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f72.google.com (mail-oo1-f72.google.com [209.85.161.72]) (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 6D5552D94AC for ; Fri, 27 Feb 2026 13:49:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772200174; cv=none; b=KLKz56r1Cg0ao7mUmVqozdUAnFYRLKg7xvaTo92Vf4IClozVl9nw79FBuYeAasPlAWw5jX3hkw5dBqG0lFGtfa1HKfMt1hAU7STKRa0bNRNMTn6UV6j8I47oEPuvxL2GiTB65eCoatsom2oWCo6TEThmRhZujCjiLM5eqY9hbsg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772200174; c=relaxed/simple; bh=YMDMC8FEVtqZlH7IsvBTLPfDjmYHZyM6F6jDfk2fB5w=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=E+mfOmahGZN0VoU0bYPBRLywrLfNGCXc+j4lph9YiaRInUiMci5fEirQph70xFYyZ57dKrdY9Q5Sp37I2gQlAGe6TFSiehJBPwR1PW9byCRPbucvfI4UVbzGgCSYMfuI+WApJtPaR90/rT5laViTbzP7yiVSpiCt73JHNOTEEGg= 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=209.85.161.72 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-f72.google.com with SMTP id 006d021491bc7-678f3fef828so715799eaf.1 for ; Fri, 27 Feb 2026 05:49:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772200171; x=1772804971; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=t9GvV4edThET8ZS8pVmyfj1XanVmMwu7Dpx+u7H+L3Q=; b=OzLL8RD0hWGtfbiyprahcXiDpObCntU7KcodXx1s0hyI0GlxTbqfT46FL9zIy6uHx3 QTWs05WdCTr/Ue8X8Fi9/Mmw9Shi0HtuWiGJoC3ZdEq/ldww1OLzDjxL+AHPdbCO3kDc s1v9ExB1PlIdVi2YvGraIV/r1MTJ9ltQhVsluwAvx6/9i2CKGfpiNbXrJvR9WgFRmX0f quYl4O5LrM1eodLWSiBT7QhsmN3g1Qt0Nxc9WfibG3+vIfu49R7cqPkeWB2jiSdtasWY bSDOj0P0f0uXTGVGCNZ7S08/ldyL1ibi0X8Y0MrfXTpj68pLCU2n8PmwYmPSHD54LpbH 0DTw== X-Forwarded-Encrypted: i=1; AJvYcCVMmUyn3KRE7h0mT9aX6FlwnbNlclZnfldIzTlIXomOTh7y3oBkcQ7tkDmkKkaF3JVePM6rSf2M4z8s@vger.kernel.org X-Gm-Message-State: AOJu0Ywrvy6IHgpp4lGYG45ObgPwYb0V/gtsLQ23rWHfRIy466tBYtDY N1ejCH2duh+3mw+pGo+Mc8eEn4faReBZ9o+MFNEJE8Pj2sZP1QvtU+p6EsGxRwelKLsk7WAuv5p tbUDUisid0ufsKeG9XAPK2Qn1otvYJjxjCvM+beHbG2y6uT8DflwWcUishD4= Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4410:b0:679:8a47:abab with SMTP id 006d021491bc7-679faf8a790mr1482868eaf.71.1772200171470; Fri, 27 Feb 2026 05:49:31 -0800 (PST) Date: Fri, 27 Feb 2026 05:49:31 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69a1a0eb.050a0220.3a55be.0021.GAE@google.com> Subject: [syzbot] [ext4?] INFO: task hung in filename_rmdir From: syzbot To: brauner@kernel.org, jack@suse.cz, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 6de23f81a5e0 Linux 7.0-rc1 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=176ad9e6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d91443204e48b7a1 dashboard link: https://syzkaller.appspot.com/bug?extid=512459401510e2a9a39f compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14630202580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11dd4006580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a3fcd7d8bed6/disk-6de23f81.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4956764f8450/vmlinux-6de23f81.xz kernel image: https://storage.googleapis.com/syzbot-assets/b9f8616ac66b/bzImage-6de23f81.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/6c600d0e3ce2/mount_0.gz fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=1779655a580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+512459401510e2a9a39f@syzkaller.appspotmail.com INFO: task syz.0.17:5981 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:29024 pid:5981 tgid:5976 ppid:5922 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x14fb/0x52c0 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:244 inode_lock_nested include/linux/fs.h:1073 [inline] __start_dirop fs/namei.c:2923 [inline] start_dirop fs/namei.c:2934 [inline] filename_rmdir+0x1cd/0x520 fs/namei.c:5386 __do_sys_rmdir fs/namei.c:5416 [inline] __se_sys_rmdir+0x2e/0x140 fs/namei.c:5413 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd6182ac629 RSP: 002b:00007fd6178e5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007fd618526090 RCX: 00007fd6182ac629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00002000000000c0 RBP: 00007fd618342b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd618526128 R14: 00007fd618526090 R15: 00007fff2f2a73b8 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:3/58: 3 locks held by kworker/1:2/863: #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90004ca7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90004ca7c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88805aa3e260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490 2 locks held by getty/5552: #0: ffff8880370f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 6 locks held by syz.0.17/5977: 2 locks held by syz.0.17/5981: #0: ffff88803704c480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880445acbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff8880445acbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff8880445acbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff8880445acbf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 5 locks held by syz.1.18/6004: 2 locks held by syz.1.18/6008: #0: ffff888027ddc480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805812b430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805812b430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88805812b430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88805812b430 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 7 locks held by syz.2.19/6030: 2 locks held by syz.2.19/6034: #0: ffff888036f74480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff8880581c6f90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff8880581c6f90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff8880581c6f90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff8880581c6f90 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 8 locks held by syz.3.20/6059: 2 locks held by syz.3.20/6063: #0: ffff88803c04c480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88804005c010 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88804005c010 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88804005c010 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88804005c010 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 7 locks held by syz.4.21/6098: 2 locks held by syz.4.21/6102: #0: ffff88803297c480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805812e3b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805812e3b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88805812e3b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88805812e3b0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 7 locks held by syz.5.22/6133: 2 locks held by syz.5.22/6137: #0: ffff88805b0a8480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888058311c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888058311c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff888058311c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff888058311c70 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 2 locks held by syz.6.23/6167: #0: ffff88805e904480 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff888044774bf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff888044774bf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff888044774bf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff888044774bf0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_rmdir+0x1cd/0x520 fs/namei.c:5386 7 locks held by syz.6.23/6172: 2 locks held by syz-executor/6180: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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: 58 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:__lock_acquire+0x273/0x2cf0 kernel/locking/lockdep.c:-1 Code: e8 f2 93 39 03 4d 89 f1 48 8b 74 24 18 44 8b 74 24 20 48 83 bc 24 20 01 00 00 00 0f 85 ce fe ff ff 44 89 74 24 20 44 89 3c 24 <8b> bc 24 38 01 00 00 4c 8b 84 24 28 01 00 00 4c 8b 74 24 08 4d 8d RSP: 0018:ffffc9000124f800 EFLAGS: 00000046 RAX: 0000000000000113 RBX: 0000000000000000 RCX: ffffffff92f693f0 RDX: 0000000000000005 RSI: 000000000000000b RDI: ffffffff8ddcd780 RBP: 0000000000000005 R08: 0000000000000000 R09: ffffffff8ddcd780 R10: dffffc0000000000 R11: fffffbfff1ed44b7 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126443000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe67c399068 CR3: 0000000039862000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline] rt_spin_lock+0x1fc/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] __batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:173 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 --- 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