WARNING: possible circular locking dependency detected 4.14.306-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/12456 is trying to acquire lock: ("%s-%s""btrfs", name){+.+.}, at: [] flush_workqueue+0xcb/0x1310 kernel/workqueue.c:2622 but task is already holding lock: (&fs_info->scrub_lock){+.+.}, at: [] btrfs_scrub_dev+0x506/0xcd0 fs/btrfs/scrub.c:4217 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&fs_info->scrub_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 btrfs_scrub_dev+0x1f3/0xcd0 fs/btrfs/scrub.c:4150 btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline] btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 -> #2 (&fs_devs->device_list_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:756 [inline] __mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893 __reada_start_machine fs/btrfs/reada.c:765 [inline] reada_start_machine_worker+0x1d2/0xa90 fs/btrfs/reada.c:746 normal_work_helper+0x304/0x1330 fs/btrfs/async-thread.c:376 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406 -> #1 ((&work->normal_work)){+.+.}: process_one_work+0x736/0x14a0 kernel/workqueue.c:2093 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:406 -> #0 ("%s-%s""btrfs", name){+.+.}: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116 __btrfs_destroy_workqueue fs/btrfs/async-thread.c:436 [inline] btrfs_destroy_workqueue+0xf8/0x630 fs/btrfs/async-thread.c:447 scrub_workers_put+0x90/0x1a0 fs/btrfs/scrub.c:4075 btrfs_scrub_dev+0x536/0xcd0 fs/btrfs/scrub.c:4219 btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline] btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 other info that might help us debug this: Chain exists of: "%s-%s""btrfs", name --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_info->scrub_lock); lock(&fs_devs->device_list_mutex); lock(&fs_info->scrub_lock); lock("%s-%s""btrfs", name); *** DEADLOCK *** 1 lock held by syz-executor.2/12456: #0: (&fs_info->scrub_lock){+.+.}, at: [] btrfs_scrub_dev+0x506/0xcd0 fs/btrfs/scrub.c:4217 stack backtrace: CPU: 0 PID: 12456 Comm: syz-executor.2 Not tainted 4.14.306-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x281 lib/dump_stack.c:58 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1258 check_prev_add kernel/locking/lockdep.c:1905 [inline] check_prevs_add kernel/locking/lockdep.c:2022 [inline] validate_chain kernel/locking/lockdep.c:2464 [inline] __lock_acquire+0x2e0e/0x3f20 kernel/locking/lockdep.c:3491 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625 drain_workqueue+0x177/0x3e0 kernel/workqueue.c:2790 destroy_workqueue+0x71/0x710 kernel/workqueue.c:4116 __btrfs_destroy_workqueue fs/btrfs/async-thread.c:436 [inline] btrfs_destroy_workqueue+0xf8/0x630 fs/btrfs/async-thread.c:447 scrub_workers_put+0x90/0x1a0 fs/btrfs/scrub.c:4075 btrfs_scrub_dev+0x536/0xcd0 fs/btrfs/scrub.c:4219 btrfs_ioctl_scrub fs/btrfs/ioctl.c:4451 [inline] btrfs_ioctl+0xba8/0x5b20 fs/btrfs/ioctl.c:5681 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x5e/0xd3 RIP: 0033:0x7f7124c8e0f9 RSP: 002b:00007f7123200168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7124dadf80 RCX: 00007f7124c8e0f9 RDX: 0000000020000100 RSI: 00000000c400941b RDI: 0000000000000004 RBP: 00007f7124ce9ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa9a1806f R14: 00007f7123200300 R15: 0000000000022000 UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) BTRFS info (device loop2): enabling inode map caching BTRFS info (device loop2): trying to use backup root at mount time BTRFS info (device loop2): use zlib compression BTRFS info (device loop2): enabling ssd optimizations BTRFS info (device loop2): using spread ssd allocation scheme BTRFS info (device loop2): using free space tree BTRFS info (device loop2): has skinny extents print_req_error: I/O error, dev loop3, sector 0 print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 24 Buffer I/O error on dev loop3, logical block 3, async page read UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2022/11/22 14:59 (1000) BTRFS info (device loop2): enabling inode map caching BTRFS info (device loop2): trying to use backup root at mount time BTRFS info (device loop2): use zlib compression BTRFS info (device loop2): enabling ssd optimizations BTRFS info (device loop2): using spread ssd allocation scheme BTRFS info (device loop2): using free space tree BTRFS info (device loop2): has skinny extents EXT4-fs (loop3): invalid inodes per group: 204800 print_req_error: I/O error, dev loop3, sector 0 Buffer I/O error on dev loop3, logical block 0, async page read print_req_error: I/O error, dev loop3, sector 4 Buffer I/O error on dev loop3, logical block 2, async page read Buffer I/O error on dev loop3, logical block 3, async page read EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Ignoring removed mblk_io_submit option EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Unsupported blocksize for fs encryption EXT4-fs (loop3): invalid inodes per group: 204800 BTRFS info (device loop5): enabling inode map caching BTRFS info (device loop5): trying to use backup root at mount time BTRFS info (device loop5): use zlib compression BTRFS info (device loop5): enabling ssd optimizations BTRFS info (device loop5): using spread ssd allocation scheme BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents mmap: syz-executor.0 (12786) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. EXT4-fs (loop3): invalid inodes per group: 204800 EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Ignoring removed mblk_io_submit option hfs: unable to open extent tree hfs: can't find a HFS filesystem on dev loop4 EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Unsupported blocksize for fs encryption EXT4-fs (loop3): invalid inodes per group: 204800 hfs: unable to open extent tree hfs: can't find a HFS filesystem on dev loop4 BTRFS info (device loop5): enabling inode map caching BTRFS info (device loop5): trying to use backup root at mount time BTRFS info (device loop5): use zlib compression hfs: unable to open extent tree BTRFS info (device loop5): enabling ssd optimizations hfs: can't find a HFS filesystem on dev loop4 BTRFS info (device loop5): using spread ssd allocation scheme BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents hfs: unable to open extent tree hfs: can't find a HFS filesystem on dev loop4 EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Ignoring removed mblk_io_submit option EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Unsupported blocksize for fs encryption EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Ignoring removed mblk_io_submit option EXT4-fs (loop1): Ignoring removed nobh option EXT4-fs (loop1): Unsupported blocksize for fs encryption