From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f69.google.com (mail-oo1-f69.google.com [209.85.161.69]) (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 238FA2C234B for ; Thu, 26 Feb 2026 09:36:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772098587; cv=none; b=uooPT71H2piCOLs0o7/zCP9NBd6zKKlLK3H1yKkbldpFIKwyxEhljQU/9C9bJJj1OdnsUlWFG2aA4dPj7IGVokBgGP61ahIqjRh/i94e/of3fqzMgcCdy8/QZkjBw3LXSCmbyGf4gn+iOwmQqRDcxTJR9yEeIghfj84SaswgByM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772098587; c=relaxed/simple; bh=Sj2G2rYSSqUMQWXehdan4EOq1qABduhja6SpnRKxnL4=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=fc4BjSW4VoWKgObifXkKRQLzp7X+8XWWXEOPIcnGBb702RX55hrwOCeURrCSRE4vlv4QBsUgOsVoedH12lMgOb3x8Et20ZJcRQpAjTKMSEbb1r/D413iYSYUYObjiupTakjnBh6UhfyReeGMe9KUTQT6kGc+GP1WSNnsvNxLic0= 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=209.85.161.69 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-oo1-f69.google.com with SMTP id 006d021491bc7-679dda090fbso14930936eaf.2 for ; Thu, 26 Feb 2026 01:36:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772098585; x=1772703385; 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=5cG+iJlJoFCAvmvNogdGvj7PlGIWRn8LNyAQZIF90xM=; b=pvBtBERovsUjUfNJ7MDOZDBwDy2SqAxWD4y6/FMsJ1EyYbF5MlRbgs3fF6RsUEdEL3 tLNPoFxeKQqhkxE4TK7/m4k9S3rW+06m/+N3YcG20uKSaliU2LWFmTC7sPHkkWWQjKQ/ aE6MWWYXV3KODWXt0X0LI4ZqVQFeU54/kZi8ggs1RAaHNYc+Yi2b1O10LmNu6tUM3wFk aiFlFgombQ+k85SlT5pYve2OYG5EbkVSS537g8iqJj4zQfQTwpkBa2IPYWW3G+7uqUbs Rw+NlgzdK/dEZgcoGi1IeXc0mVxafteSSahC/6ZqKobr8S69Xk7Z8sOfeQ/22c3MxQST rYoQ== X-Forwarded-Encrypted: i=1; AJvYcCVNL5BIOdtxA1ASCCOU4U/0rwMiOVsChTTQTiRFJqDQzCZDtWTWdkBksZ+o77GBTVKlGASZTCbM4YD3W1Y=@vger.kernel.org X-Gm-Message-State: AOJu0Yz9RYdABf9yLFZoJQRkSpVlv+V22mU7WuW9nt5nJFG37gmjB/PY H4Lz7ZI75BZznSfkFWp2NK0YuFOuDxUbh7eTMhde214Lmvl5niKrWpNe7L4es643DJnUzD3M+SV fLEcQBAdEfhgYK6BiR/PTXKySNKF5fX56xz/RLzhh8ZclRVidHTumGdt9WxE= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:1808:b0:662:b5e0:e6d1 with SMTP id 006d021491bc7-679ef7fdfbemr1745333eaf.16.1772098585238; Thu, 26 Feb 2026 01:36:25 -0800 (PST) Date: Thu, 26 Feb 2026 01:36:25 -0800 In-Reply-To: <698cb045.050a0220.2eeac1.009b.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69a01419.050a0220.2fcbed.0008.GAE@google.com> Subject: Re: [syzbot] [ext4?] INFO: task hung in block_read_full_folio (3) 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: d9d32e5bd5a4 Merge tag 'ata-7.0-rc2' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=105ac202580000 kernel config: https://syzkaller.appspot.com/x/.config?x=93740e6c6567fcec dashboard link: https://syzkaller.appspot.com/bug?extid=03afbb29537f0336b7ad 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=151cc24a580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1218a8d6580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d223d806e90e/disk-d9d32e5b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/d2d3e2c957ed/vmlinux-d9d32e5b.xz kernel image: https://storage.googleapis.com/syzbot-assets/db3a0620bab3/bzImage-d9d32e5b.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/0e3dce03880c/mount_0.gz fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1450755a580000) IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+03afbb29537f0336b7ad@syzkaller.appspotmail.com INFO: task udevd:5880 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:24960 pid:5880 tgid:5880 ppid:5186 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:72 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] block_read_full_folio+0x38f/0x830 fs/buffer.c:2436 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2496 filemap_update_page mm/filemap.c:2583 [inline] filemap_get_pages+0x1744/0x1f10 mm/filemap.c:2713 filemap_read+0x447/0x1230 mm/filemap.c:2800 blkdev_read_iter+0x30a/0x440 block/fops.c:855 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x582/0xa70 fs/read_write.c:574 ksys_read+0x150/0x270 fs/read_write.c:717 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: 0033:0x7f30023de407 RSP: 002b:00007ffef214d590 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f3002352880 RCX: 00007f30023de407 RDX: 0000000000000200 RSI: 00007f300234e000 RDI: 0000000000000009 RBP: 0000556fb2cd5c50 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000018 R13: 0000000000001000 R14: 0000556fb2ce78f8 R15: 00007f30025f739c INFO: task syz.4.874:8117 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.874 state:D stack:25632 pid:8117 tgid:8117 ppid:5974 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323 folio_lock include/linux/pagemap.h:1170 [inline] __find_get_block_slow fs/buffer.c:206 [inline] find_get_block_common+0x34f/0xe10 fs/buffer.c:1405 bdev_getblk+0x53/0x6e0 include/linux/gfp.h:-1 __getblk include/linux/buffer_head.h:380 [inline] sb_getblk include/linux/buffer_head.h:386 [inline] __ext4_get_inode_loc+0x7d8/0xfa0 fs/ext4/inode.c:4812 ext4_get_inode_loc fs/ext4/inode.c:4915 [inline] ext4_reserve_inode_write+0x18b/0x360 fs/ext4/inode.c:6235 __ext4_mark_inode_dirty+0x14b/0x730 fs/ext4/inode.c:6413 __ext4_new_inode+0x3383/0x3d20 fs/ext4/ialloc.c:1333 ext4_mkdir+0x3da/0xbf0 fs/ext4/namei.c:3005 vfs_mkdir+0x413/0x630 fs/namei.c:5233 filename_mkdirat+0x285/0x510 fs/namei.c:5266 __do_sys_mkdir fs/namei.c:5293 [inline] __se_sys_mkdir+0x34/0x150 fs/namei.c:5290 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: 0033:0x7f08d499c629 RSP: 002b:00007ffd2b703978 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007f08d4c15fa0 RCX: 00007f08d499c629 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000680 RBP: 00007f08d4a32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f08d4c15fac R14: 00007f08d4c15fa0 R15: 00007f08d4c15fa0 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88801fabd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801fabd948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000127c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88801b6f20e0 (&type->s_umount_key#41){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565 1 lock held by khungtaskd/32: #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/127: #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by udevd/5186: 2 locks held by getty/5573: #0: ffff888032cfe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 2 locks held by udevd/5880: #0: ffff888023452a28 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888023452a28 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:854 #1: ffff888023452bc8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline] #1: ffff888023452bc8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2549 [inline] #1: ffff888023452bc8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x991/0x1f10 mm/filemap.c:2713 1 lock held by syz-executor/5965: #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz-executor/5966: 4 locks held by udevd/6188: 2 locks held by syz.4.874/8117: #0: ffff88807bcaa420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805b1d03e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline] #1: ffff88805b1d03e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline] #1: ffff88805b1d03e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline] #1: ffff88805b1d03e0 (&type->i_mutex_dir_key#3/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922 2 locks held by udevd/8626: #0: ffff888023451328 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888023451328 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:854 #1: ffff8880b873ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 1 lock held by udevd/8653: 1 lock held by udevd/8654: #0: ffff888023454128 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888023454128 (&sb->s_type->i_mutex_key#11){++++}-{4:4}, at: blkdev_read_iter+0x2f8/0x440 block/fops.c:854 2 locks held by syz.5.2965/13038: 1 lock held by syz.6.2966/13039: 1 lock held by syz.0.2964/13042: 1 lock held by kmmpd-loop0/13048: #0: ffff8880b873ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(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: 6188 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:srso_alias_safe_ret+0x0/0x7 arch/x86/lib/retpoline.S:210 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0018:ffffc90002ed73d0 EFLAGS: 00000293 RAX: ffffffff8ba52031 RBX: ffff888036ffd900 RCX: ffff88801ef73c80 RDX: 0000000000000000 RSI: 0000000000000300 RDI: 0000000000000300 RBP: 0000000000000001 R08: ffff88801ef73c80 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880760d8800 R14: ffff8880595dbdc0 R15: ffffffffffffffff FS: 00007f3002352880(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f300234d000 CR3: 000000002c631000 CR4: 0000000000350ef0 Call Trace: srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:220 mt_locked lib/maple_tree.c:729 [inline] mt_slot lib/maple_tree.c:736 [inline] mas_next_slot+0x951/0xcf0 lib/maple_tree.c:4406 mas_find+0xb0e/0xd30 lib/maple_tree.c:5622 vma_next include/linux/mm.h:1323 [inline] validate_mm+0xfe/0x4c0 mm/vma.c:650 mmap_region+0x1513/0x2240 mm/vma.c:2843 do_mmap+0xc39/0x10c0 mm/mmap.c:559 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581 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: 0033:0x7f3002454822 Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 a1 35 0d 00 64 RSP: 002b:00007ffef214d608 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3002454822 RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000 RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000008000 R14: 0000556fb2cd30b0 R15: 0000000000004000 --- 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.