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 5D84625522B for ; Wed, 8 Oct 2025 13:07:27 +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=1759928849; cv=none; b=U9hEYvTIXTN5TVGBlM/hCajcHCkK+ifZ4kh+J5zrY6Qk9LQTmNuHIUIqc4MCx5d1OuVPssXmT7SPZRReAk8qm+X7XKnxnGV1JsneuiO+eJ/RI/rvi9y0JnAkVyF9VV80jeLSeu5nm+rp/itVuQYCVCqpP48sq9y0NfucBuRUALM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759928849; c=relaxed/simple; bh=i0lrF19IErTYbbVG+UY1LEim06Ab43fposzYwrg0id4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=pUAo3p3/LxuMv8BnIXStLa2aAemfgmj8OjCaRmz9Q80nCPVR9+PzEAh0kJrjqJinwl3UyKHLyue1xoNvYXDXZt9P9f1q5t+GCt9acIraD7vghcekqFLyVEUbwoE2BiglFVBg8GpYdwk0r0VX6obr1yzx0WwQoxV01yCXRWsC+fU= 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-42594b7f324so21031175ab.1 for ; Wed, 08 Oct 2025 06:07:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759928846; x=1760533646; 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=cQCSSWeDYUbVW+Ju6kzqoilJ5OIw0y/nQnioY7MchMs=; b=bl4SIzPO6lSN+iN6lsLwnqQzTTmyi/KuOsIBjSP7bhWiKE7CzyqzCrv+YTOg8wTjcf jb2oCpFfhKbt7+4R7oRV/ly3vtdiMjduK63x6EkVOr1zZYn1IWDVeVslpFU/rsrK0gCi p0GqTp2PRiq4ob6y2fqxbsprIld5M0ja0HpqgKtyWBhwf2EmOf7MJ1yxaERsYwQajDo9 0wcBEdfOcKVLiOx/euMLSwESfr0Yd5jRq4a/ZpidFZbUt8zWDfI73/v/xrkbFW3IWb5F yr3h6BAqONBm4rwBuGGgqWAyRiSaKj1Q7gz4AOhpf3vxgAXLDku8na5B/jibP0vzHUER sHiA== X-Forwarded-Encrypted: i=1; AJvYcCWBdHZNuNHf9QWFa0C0w14SLcweJLUvcMPol+v17C4CrmWKEzPzb8DakSZIELbEANR7kZpkpS/YReQh@vger.kernel.org X-Gm-Message-State: AOJu0YxNUp5QIvmyTmnHtaRFjIHv3IG14YSHO389SqnnEGJclyv5rBv0 1s90O8mMAwngA5+Mr5TVvfAHPC/0nV9VqaWuGnOBXApe6EEGicyyDTsXrtTvIj0eQcWLuCzse4o oPGzgjsXPrVbPTx0i1vVU5Tlqc1WCES0FpTpeY+9XDGDghJ1tITb8ELIpJK8= X-Google-Smtp-Source: AGHT+IEHLDKnfsjCQYsF9bazIbCdMmwOhnBBRGrKPju1XxQORy3HOk0OyQHK9b5VEOGXL3RL43IAdWGekisM2Ygec5DwhK5TbbQ6 Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1fce:b0:422:a9aa:7ff4 with SMTP id e9e14a558f8ab-42f874727c4mr26322605ab.11.1759928846107; Wed, 08 Oct 2025 06:07:26 -0700 (PDT) Date: Wed, 08 Oct 2025 06:07:26 -0700 In-Reply-To: <6768bb8e.050a0220.2f3838.0012.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68e6620e.050a0220.256323.003a.GAE@google.com> Subject: Re: [syzbot] [ext4?] INFO: task hung in find_inode_fast (4) From: syzbot To: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tytso@mit.edu Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: 971199ad2a0f Merge tag 'arm64-fixes' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1503c1e2580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d115f113a86997de dashboard link: https://syzkaller.appspot.com/bug?extid=fd5533bcd0f7343bb8ca compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12dc052f980000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10d3da7c580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/406943a8345c/disk-971199ad.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/06d218aee5c4/vmlinux-971199ad.xz kernel image: https://storage.googleapis.com/syzbot-assets/56c432aaadf2/bzImage-971199ad.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/cc46824d9bfa/mount_0.gz fsck result: OK (log: https://syzkaller.appspot.com/x/fsck.log?x=1719f334580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fd5533bcd0f7343bb8ca@syzkaller.appspotmail.com INFO: task syz.1.551:8496 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.551 state:D stack:24424 pid:8496 tgid:8495 ppid:5991 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 __wait_on_freeing_inode+0x1c5/0x2f0 fs/inode.c:2494 find_inode_fast+0x2b0/0x470 fs/inode.c:1070 iget_locked+0xaf/0x580 fs/inode.c:1433 __ext4_iget+0x242/0x41c0 fs/ext4/inode.c:5210 ext4_xattr_inode_cache_find fs/ext4/xattr.c:1545 [inline] ext4_xattr_inode_lookup_create+0x438/0x1c20 fs/ext4/xattr.c:1584 ext4_xattr_ibody_set+0x202/0x6a0 fs/ext4/xattr.c:2263 ext4_xattr_set_handle+0xc9a/0x1590 fs/ext4/xattr.c:2440 ext4_xattr_set+0x230/0x320 fs/ext4/xattr.c:2554 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_setxattr fs/xattr.c:747 [inline] __se_sys_setxattr fs/xattr.c:743 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdacd18eec9 RSP: 002b:00007fdace024038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007fdacd3e5fa0 RCX: 00007fdacd18eec9 RDX: 0000200000001400 RSI: 00002000000001c0 RDI: 0000200000000380 RBP: 00007fdacd211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdacd3e6038 R14: 00007fdacd3e5fa0 R15: 00007fff7468a358 INFO: task syz.1.551:8508 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.551 state:D stack:26056 pid:8508 tgid:8495 ppid:5991 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 mb_cache_entry_wait_unused+0x165/0x250 fs/mbcache.c:148 ext4_evict_ea_inode+0x14d/0x2f0 fs/ext4/xattr.c:481 ext4_evict_inode+0x16f/0xee0 fs/ext4/inode.c:183 evict+0x504/0x9c0 fs/inode.c:810 ext4_xattr_ibody_set+0x510/0x6a0 fs/ext4/xattr.c:2281 ext4_xattr_set_handle+0xc9a/0x1590 fs/ext4/xattr.c:2440 ext4_xattr_set+0x230/0x320 fs/ext4/xattr.c:2554 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_setxattr fs/xattr.c:747 [inline] __se_sys_setxattr fs/xattr.c:743 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdacd18eec9 RSP: 002b:00007fdace003038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007fdacd3e6090 RCX: 00007fdacd18eec9 RDX: 0000200000001400 RSI: 00002000000001c0 RDI: 0000200000000200 RBP: 00007fdacd211f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000835 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdacd3e6128 R14: 00007fdacd3e6090 R15: 00007fff7468a358 Showing all locks held in the system: 5 locks held by kworker/u8:0/12: 1 lock held by ksoftirqd/1/23: #0: ffff888024985b18 (&fq->mq_flush_lock){..-.}-{3:3}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 1 lock held by khungtaskd/31: #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13d320 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5577: #0: ffff88814d3930a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by udevd/5892: #0: ffff888140ac0188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5d0 fs/kernfs/dir.c:1180 2 locks held by syz-executor/5988: #0: ffff888024845358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128 #1: ffff8880b863a058 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:638 1 lock held by syz-executor/5999: 1 lock held by syz-executor/6000: 1 lock held by syz-executor/6003: #0: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e142db8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 3 locks held by syz.1.551/8496: #0: ffff88807b85c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff888058a1ed10 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff888058a1ed10 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff888058a1e9f8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888058a1e9f8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_set_handle+0x165/0x1590 fs/ext4/xattr.c:2367 3 locks held by syz.1.551/8508: #0: ffff88807b85c420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508 #1: ffff888058a02a20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline] #1: ffff888058a02a20 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff888058a02708 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] #2: ffff888058a02708 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_set_handle+0x165/0x1590 fs/ext4/xattr.c:2367 3 locks held by syz.0.1661/13268: 1 lock held by syz.3.1660/13273: 1 lock held by syz.6.1659/13274: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 13273 Comm: syz.3.1660 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400 Code: e8 6e 6e a4 fc 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf 0c 0a fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 55 1b f5 fb cc 44 89 f9 80 e1 07 RSP: 0018:ffffc9000e50f270 EFLAGS: 00000002 RAX: 1ffffffff33a2900 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffffff99d14e70 R08: ffff8880240a0237 R09: 1ffff11004814046 R10: dffffc0000000000 R11: ffffffff851b2530 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff99d14be0 R15: 0000000000000000 FS: 00007f6d1fcb56c0(0000) GS:ffff888125e12000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b77495000 CR3: 0000000026505000 CR4: 0000000000350ef0 Call Trace: serial_in drivers/tty/serial/8250/8250.h:137 [inline] serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline] wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3111 [inline] console_flush_all+0x6f3/0xb10 kernel/printk/printk.c:3199 __console_flush_and_unlock kernel/printk/printk.c:3258 [inline] console_unlock+0xbb/0x190 kernel/printk/printk.c:3298 vprintk_emit+0x4c5/0x590 kernel/printk/printk.c:2423 _printk+0xcf/0x120 kernel/printk/printk.c:2448 __ext4_msg+0x20a/0x2a0 fs/ext4/super.c:992 ext4_parse_param+0x3b3/0x24c0 fs/ext4/super.c:-1 vfs_parse_fs_param+0x1a9/0x420 fs/fs_context.c:146 vfs_parse_fs_qstr fs/fs_context.c:187 [inline] vfs_parse_fs_string include/linux/fs_context.h:142 [inline] vfs_parse_monolithic_sep+0x25d/0x320 fs/fs_context.c:227 do_new_mount+0x2cb/0xa10 fs/namespace.c:3723 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6d1ed9066a Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f6d1fcb4e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f6d1fcb4ef0 RCX: 00007f6d1ed9066a RDX: 0000200000000040 RSI: 0000200000000140 RDI: 00007f6d1fcb4eb0 RBP: 0000200000000040 R08: 00007f6d1fcb4ef0 R09: 0000000000200044 R10: 0000000000200044 R11: 0000000000000246 R12: 0000200000000140 R13: 00007f6d1fcb4eb0 R14: 000000000000056a R15: 000000000000002c --- 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.