syzbot has found a reproducer for the following issue on: HEAD commit: 2cf0f7156238 Merge tag 'nfs-for-6.6-2' of git://git.linux-.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=12780282680000 kernel config: https://syzkaller.appspot.com/x/.config?x=710dc49bece494df dashboard link: https://syzkaller.appspot.com/bug?extid=062317ea1d0a6d5e29e7 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=107e9518680000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/f48f4ed701b8/disk-2cf0f715.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/5b8491e29a2d/vmlinux-2cf0f715.xz kernel image: https://storage.googleapis.com/syzbot-assets/90faa04d6558/bzImage-2cf0f715.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/c98194587df7/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+062317ea1d0a6d5e29e7@xxxxxxxxxxxxxxxxxxxxxxxxx ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0 Not tainted ------------------------------------------------------ syz-executor.0/8792 is trying to acquire lock: ffff88807993a0e0 (&type->s_umount_key#25){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline] ffff88807993a0e0 (&type->s_umount_key#25){++++}-{3:3}, at: super_lock+0x23c/0x380 fs/super.c:117 but task is already holding lock: ffff888148439388 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_flushbuf block/ioctl.c:370 [inline] ffff888148439388 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_common_ioctl+0x14e9/0x1ce0 block/ioctl.c:502 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&bdev->bd_holder_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x181/0x1340 kernel/locking/mutex.c:747 bdev_mark_dead+0x25/0x230 block/bdev.c:961 disk_force_media_change+0x51/0x80 block/disk-events.c:303 __loop_clr_fd+0x3ab/0x8f0 drivers/block/loop.c:1174 lo_release+0x188/0x1c0 drivers/block/loop.c:1743 blkdev_put_whole+0xa5/0xe0 block/bdev.c:663 blkdev_put+0x40f/0x8e0 block/bdev.c:898 kill_block_super+0x58/0x70 fs/super.c:1649 deactivate_locked_super+0x9a/0x170 fs/super.c:481 deactivate_super+0xde/0x100 fs/super.c:514 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254 task_work_run+0x14d/0x240 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x60 kernel/entry/common.c:296 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x181/0x1340 kernel/locking/mutex.c:747 blkdev_get_by_dev.part.0+0x4f0/0xb20 block/bdev.c:786 blkdev_get_by_dev+0x75/0x80 block/bdev.c:829 journal_init_dev fs/reiserfs/journal.c:2626 [inline] journal_init+0xbb8/0x64b0 fs/reiserfs/journal.c:2786 reiserfs_fill_super+0xcc6/0x3150 fs/reiserfs/super.c:2022 mount_bdev+0x1f3/0x2e0 fs/super.c:1629 legacy_get_tree+0x109/0x220 fs/fs_context.c:638 vfs_get_tree+0x8c/0x370 fs/super.c:1750 do_new_mount fs/namespace.c:3335 [inline] path_mount+0x1492/0x1ed0 fs/namespace.c:3662 do_mount fs/namespace.c:3675 [inline] __do_sys_mount fs/namespace.c:3884 [inline] __se_sys_mount fs/namespace.c:3861 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:3861 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&type->s_umount_key#25){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 down_read+0x9c/0x470 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x23c/0x380 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1431 [inline] fs_bdev_sync+0x94/0x1b0 fs/super.c:1466 blkdev_flushbuf block/ioctl.c:372 [inline] blkdev_common_ioctl+0x1550/0x1ce0 block/ioctl.c:502 blkdev_ioctl+0x249/0x770 block/ioctl.c:624 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &type->s_umount_key#25 --> &disk->open_mutex --> &bdev->bd_holder_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&bdev->bd_holder_lock); lock(&disk->open_mutex); lock(&bdev->bd_holder_lock); rlock(&type->s_umount_key#25); *** DEADLOCK *** 1 lock held by syz-executor.0/8792: #0: ffff888148439388 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_flushbuf block/ioctl.c:370 [inline] #0: ffff888148439388 (&bdev->bd_holder_lock){+.+.}-{3:3}, at: blkdev_common_ioctl+0x14e9/0x1ce0 block/ioctl.c:502 stack backtrace: CPU: 0 PID: 8792 Comm: syz-executor.0 Not tainted 6.6.0-rc2-syzkaller-00018-g2cf0f7156238 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x311/0x3f0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 down_read+0x9c/0x470 kernel/locking/rwsem.c:1520 __super_lock fs/super.c:58 [inline] super_lock+0x23c/0x380 fs/super.c:117 super_lock_shared fs/super.c:146 [inline] super_lock_shared_active fs/super.c:1431 [inline] fs_bdev_sync+0x94/0x1b0 fs/super.c:1466 blkdev_flushbuf block/ioctl.c:372 [inline] blkdev_common_ioctl+0x1550/0x1ce0 block/ioctl.c:502 blkdev_ioctl+0x249/0x770 block/ioctl.c:624 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl fs/ioctl.c:857 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f18ae67cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f18af4830c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f18ae79bf80 RCX: 00007f18ae67cae9 RDX: 0000000000000003 RSI: 0000000000001261 RDI: 0000000000000003 RBP: 00007f18ae6c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f18ae79bf80 R15: 00007ffc4185a478 </TASK> --- 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.
