From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f207.google.com (mail-oi1-f207.google.com [209.85.167.207]) (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 AA4A03D8907 for ; Thu, 20 Aug 2026 21:02:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787259749; cv=none; b=F7CmPQInAGQC1KR44jqPkoPoeHRU23CA2BKix2+kZ7VtbeNZO/WSKtporcyrz79KOwryTsnjZ2xWESKd0PxGGSlpCwkwOX9gKjfeeDC8dPpJq3JBbF7cq3W1C5hfVUMFJDiZfEGUYBYuPrJYqWl7Q3thh/iHp8mrMGS22UPMqgk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787259749; c=relaxed/simple; bh=svUM0Mp+YSR8yTwMicGs3ZmGDvzIZktVo9Q2lXQgO2c=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=umZgWulcd4JFzrGrggXmZxuTKODtpiJV3TDSsIJwDMqfEHELd3V4W6Q5ZWbpA8fSBWWWfmaQcXwj1ra82NNwCxweWcKBiNIR92Otpe1nKOVqnZ3hOcXooS5gcOfc/bwvhXNktzPR7HtcfoczzrYfHbN19mphAtR9ZZDrU2FxHdM= 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=209.85.167.207 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-oi1-f207.google.com with SMTP id 5614622812f47-4ad778bacbeso495267b6e.1 for ; Thu, 20 Aug 2026 14:02:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787259746; x=1787864546; h=content-transfer-encoding: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=GB4j5ZzEbHNjh+qE2dE1EgxaCeO9pNVK6hZY0hWhFP8=; b=sugoILO/0KwmWnosaabyFHVF8usItSeE7TZT+fPFJD/Y/QAGCH8ZRPwdwJPSbLQnX1 J51Z99mG3tHf6yfDcejy+h3kc18kIljRgFs+XPUeQ3vVXXz4CT6zR0dSiNWhKW3Jsyhg 4/YMsc8QpQNJFIyxdTqwGBPPVCKriSM958MSr7B7ihzVU3Khf/rJKtTYtslu1Is7prNj v8lJAXzOd653ZL0VbG3XzPWY2TQVeOh7bq/4F4lYwy9jGKrw/DVvYV0rdaIf43fPy0Wc PcYcG9ZU84W0UYOsA3dBdWW29mS+4sPIMfoBZD4pITfyOL6RcdymGcfYDWOsHgYRhzR8 E77w== X-Forwarded-Encrypted: i=1; AHgh+Ro6SBZay2jGqTBa8ZeA04nIPoB3dOKwJBsh+CBeT+noNmioD824HvoWvjKEL0WAO9KpXbueyI4et0hama0=@vger.kernel.org X-Gm-Message-State: AOJu0YwrTaOV9gUze8P90yY2cZnOsnuJHTxKIJfZuyy+iUU+d7zPA6iF OaheI2crdQdQgVT73TSGevERdXZuuVx11+eEIuRMi+HPP4pBCkhMyHpYVhkK4DkJAUoIa3Suels Nm+ZtgBPeeb70bfYlyTlfDfD+wHJDHZykbRdbE+AbIbLQAJnb6FfM3DQASsU= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:1188:b0:4b2:3e72:bab1 with SMTP id 5614622812f47-4b2ef24f8e1mr1021177b6e.6.1787259746343; Thu, 20 Aug 2026 14:02:26 -0700 (PDT) Date: Thu, 20 Aug 2026 14:02:26 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a876b62.4d75e56a.c9a88.004b.GAE@google.com> Subject: [syzbot] [block?] possible deadlock in ocfs2_read_blocks (2) From: syzbot To: axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello, syzbot found the following issue on: HEAD commit: 4477a78374a5 Add linux-next specific files for 20260814 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=3D129b9949580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3D9b32a36dd637b06= f dashboard link: https://syzkaller.appspot.com/bug?extid=3Db03f9cd50db23adee= b71 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-= 1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/994c1c8c560e/disk-= 4477a783.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/cd54543d69ae/vmlinux-= 4477a783.xz kernel image: https://storage.googleapis.com/syzbot-assets/407cdf8f3fc2/bzI= mage-4477a783.xz IMPORTANT: if you fix the issue, please add the following tag to the commit= : Reported-by: syzbot+b03f9cd50db23adeeb71@syzkaller.appspotmail.com =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L =20 ------------------------------------------------------ syz.3.993/9951 is trying to acquire lock: ffff8880724887d0 (&oi->ip_io_mutex){+.+.}-{4:4}, at: ocfs2_read_blocks+0x1e= f/0x14d0 fs/ocfs2/buffer_head_io.c:229 but task is already holding lock: ffff888026afda68 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_upda= te include/linux/blkdev.h:1101 [inline] ffff888026afda68 (&q->limits_lock){+.+.}-{4:4}, at: loop_configure+0x787/0x= dc0 drivers/block/loop.c:1083 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&q->limits_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 queue_limits_start_update include/linux/blkdev.h:1101 [inline] loop_set_dio drivers/block/loop.c:1460 [inline] lo_simple_ioctl drivers/block/loop.c:1528 [inline] lo_ioctl+0x16ca/0x2150 drivers/block/loop.c:1594 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#24){++++}-{0:0}: bio_queue_enter block/blk.h:95 [inline] blk_mq_submit_bio+0x7f8/0x2a70 block/blk-mq.c:3127 __submit_bio_noacct_mq block/blk-core.c:756 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790 ocfs2_read_blocks+0x85e/0x14d0 fs/ocfs2/buffer_head_io.c:324 ocfs2_read_inode_block_full fs/ocfs2/inode.c:1968 [inline] ocfs2_read_inode_block+0xe0/0x190 fs/ocfs2/inode.c:1980 ocfs2_get_clusters+0x341/0xc00 fs/ocfs2/extent_map.c:625 ocfs2_extent_map_get_blocks+0x202/0x6a0 fs/ocfs2/extent_map.c:678 ocfs2_read_virt_blocks+0x283/0x9c0 fs/ocfs2/extent_map.c:1001 ocfs2_read_dir_block fs/ocfs2/dir.c:522 [inline] ocfs2_find_entry_el fs/ocfs2/dir.c:790 [inline] ocfs2_find_entry+0x3c3/0x2050 fs/ocfs2/dir.c:1165 ocfs2_find_files_on_disk+0xe0/0x340 fs/ocfs2/dir.c:2082 ocfs2_lookup_ino_from_name+0x52/0x100 fs/ocfs2/dir.c:2104 _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:133 [inline] ocfs2_get_system_file_inode+0x32f/0x810 fs/ocfs2/sysfile.c:110 ocfs2_init_global_system_inodes+0x318/0x6e0 fs/ocfs2/super.c:461 ocfs2_initialize_super fs/ocfs2/super.c:2192 [inline] ocfs2_fill_super+0x456e/0x6840 fs/ocfs2/super.c:993 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1887 vfs_get_tree+0x92/0x2a0 fs/super.c:1947 fc_mount fs/namespace.c:1198 [inline] do_new_mount_fc fs/namespace.c:3772 [inline] do_new_mount+0x319/0xdc0 fs/namespace.c:3848 do_mount fs/namespace.c:4181 [inline] __do_sys_mount fs/namespace.c:4397 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4374 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&oi->ip_io_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 ocfs2_read_blocks+0x1ef/0x14d0 fs/ocfs2/buffer_head_io.c:229 ocfs2_read_inode_block_full fs/ocfs2/inode.c:1968 [inline] ocfs2_read_inode_block+0xe0/0x190 fs/ocfs2/inode.c:1980 ocfs2_assign_bh fs/ocfs2/dlmglue.c:2415 [inline] ocfs2_inode_lock_full_nested+0x2bb/0x1b30 fs/ocfs2/dlmglue.c:2510 ocfs2_statfs+0x1ba/0xa70 fs/ocfs2/super.c:1577 statfs_by_dentry fs/statfs.c:66 [inline] vfs_statfs+0x147/0x2d0 fs/statfs.c:90 loop_get_discard_config drivers/block/loop.c:774 [inline] loop_update_limits+0x375/0x920 drivers/block/loop.c:984 loop_configure+0x7d2/0xdc0 drivers/block/loop.c:1084 lo_ioctl+0xad5/0x2150 drivers/block/loop.c:1564 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &oi->ip_io_mutex --> &q->q_usage_counter(io)#24 --> &q->limits_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->limits_lock); lock(&q->q_usage_counter(io)#24); lock(&q->limits_lock); lock(&oi->ip_io_mutex); *** DEADLOCK *** locks held by syz.3.993/9951: 2, last CPU#1: #0: ffff888026af3430 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_global_lock_kil= lable drivers/block/loop.c:119 [inline] #0: ffff888026af3430 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_configure+0x35d= /0xdc0 drivers/block/loop.c:1038 #1: ffff888026afda68 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start= _update include/linux/blkdev.h:1101 [inline] #1: ffff888026afda68 (&q->limits_lock){+.+.}-{4:4}, at: loop_configure+0x7= 87/0xdc0 drivers/block/loop.c:1083 stack backtrace: CPU: 1 UID: 0 PID: 9951 Comm: syz.3.993 Tainted: G L syzka= ller #0 PREEMPT(full)=20 Tainted: [L]=3DSOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2059 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2191 check_prev_add kernel/locking/lockdep.c:3181 [inline] check_prevs_add kernel/locking/lockdep.c:3300 [inline] validate_chain kernel/locking/lockdep.c:3924 [inline] __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 ocfs2_read_blocks+0x1ef/0x14d0 fs/ocfs2/buffer_head_io.c:229 ocfs2_read_inode_block_full fs/ocfs2/inode.c:1968 [inline] ocfs2_read_inode_block+0xe0/0x190 fs/ocfs2/inode.c:1980 ocfs2_assign_bh fs/ocfs2/dlmglue.c:2415 [inline] ocfs2_inode_lock_full_nested+0x2bb/0x1b30 fs/ocfs2/dlmglue.c:2510 ocfs2_statfs+0x1ba/0xa70 fs/ocfs2/super.c:1577 statfs_by_dentry fs/statfs.c:66 [inline] vfs_statfs+0x147/0x2d0 fs/statfs.c:90 loop_get_discard_config drivers/block/loop.c:774 [inline] loop_update_limits+0x375/0x920 drivers/block/loop.c:984 loop_configure+0x7d2/0xdc0 drivers/block/loop.c:1084 lo_ioctl+0xad5/0x2150 drivers/block/loop.c:1564 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:798 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f61a979e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 = 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff f= f 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f61aa701028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f61a9a26180 RCX: 00007f61a979e0d9 RDX: 0000200000001800 RSI: 0000000000004c0a RDI: 0000000000000005 RBP: 00007f61a9835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f61a9a26218 R14: 00007f61a9a26180 R15: 00007ffd47e4a038 loop8: detected capacity change from 0 to 7 Dev loop8: unable to read RDB block 7 loop8: unable to read partition table loop8: partition table beyond EOD, truncated loop_reread_partitions: partition scan of loop8 (=EF=BF=BD=E8=A2=ABx=EF=BF= =BD^>=EF=BF=BD) failed (rc=3D-5) --- 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 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