====================================================== WARNING: possible circular locking dependency detected 5.15.160-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.4/7837 is trying to acquire lock: ffff88805bcc9b80 (&sb->s_type->i_mutex_key#36){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:799 [inline] ffff88805bcc9b80 (&sb->s_type->i_mutex_key#36){++++}-{3:3}, at: lookup_slow+0x45/0x70 fs/namei.c:1679 but task is already holding lock: ffff888074bd28e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_free_stale_devices+0x14b/0xb00 fs/btrfs/volumes.c:603 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 btrfs_run_dev_stats+0xeb/0xfd0 fs/btrfs/volumes.c:7949 commit_cowonly_roots+0x1cb/0x9d0 fs/btrfs/transaction.c:1290 btrfs_commit_transaction+0x13af/0x3800 fs/btrfs/transaction.c:2392 sync_filesystem+0x1bc/0x220 fs/sync.c:66 generic_shutdown_super+0x6e/0x2c0 fs/super.c:448 kill_anon_super+0x37/0x60 fs/super.c:1076 btrfs_kill_super+0x3d/0x50 fs/btrfs/super.c:2391 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}: reacquire_held_locks+0x3a2/0x660 kernel/locking/lockdep.c:5150 __lock_release kernel/locking/lockdep.c:5339 [inline] lock_release+0x369/0x9a0 kernel/locking/lockdep.c:5643 __mutex_unlock_slowpath+0xde/0x750 kernel/locking/mutex.c:851 btrfs_commit_transaction+0x1e34/0x3800 fs/btrfs/transaction.c:2439 close_ctree+0x390/0x890 fs/btrfs/disk-io.c:4450 generic_shutdown_super+0x136/0x2c0 fs/super.c:475 kill_anon_super+0x37/0x60 fs/super.c:1076 btrfs_kill_super+0x3d/0x50 fs/btrfs/super.c:2391 deactivate_locked_super+0xa0/0x110 fs/super.c:335 cleanup_mnt+0x44e/0x500 fs/namespace.c:1143 task_work_run+0x129/0x1a0 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x106/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #4 (sb_internal#3){.+.+}-{0:0}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1811 [inline] sb_start_intwrite include/linux/fs.h:1928 [inline] start_transaction+0x5a8/0x11a0 fs/btrfs/transaction.c:678 btrfs_dirty_inode+0xcc/0x1c0 fs/btrfs/inode.c:6428 inode_update_time fs/inode.c:1829 [inline] file_update_time+0x3d1/0x460 fs/inode.c:2019 btrfs_page_mkwrite+0x3c0/0xd60 fs/btrfs/inode.c:8930 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2892 wp_page_shared+0x179/0x690 mm/memory.c:3229 handle_pte_fault mm/memory.c:4639 [inline] __handle_mm_fault mm/memory.c:4756 [inline] handle_mm_fault+0x2a3d/0x5950 mm/memory.c:4854 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 copy_user_generic_unrolled+0x89/0xc0 arch/x86/lib/copy_user_64.S:91 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] _copy_to_user+0xef/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] ioctl_fiemap fs/ioctl.c:224 [inline] do_vfs_ioctl+0x19cb/0x2b70 fs/ioctl.c:814 __do_sys_ioctl fs/ioctl.c:872 [inline] __se_sys_ioctl+0x81/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #3 (sb_pagefaults#4){.+.+}-{0:0}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1811 [inline] sb_start_pagefault include/linux/fs.h:1910 [inline] btrfs_page_mkwrite+0x1ef/0xd60 fs/btrfs/inode.c:8914 do_page_mkwrite+0x1a9/0x440 mm/memory.c:2892 do_shared_fault mm/memory.c:4298 [inline] do_fault mm/memory.c:4366 [inline] handle_pte_fault mm/memory.c:4621 [inline] __handle_mm_fault mm/memory.c:4756 [inline] handle_mm_fault+0x2803/0x5950 mm/memory.c:4854 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568 -> #2 (&mm->mmap_lock){++++}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __might_fault+0xb4/0x110 mm/memory.c:5328 _copy_to_user+0x28/0x130 lib/usercopy.c:35 copy_to_user include/linux/uaccess.h:200 [inline] fat_ioctl_filldir+0x1d8/0x600 fs/fat/dir.c:759 dir_emit include/linux/fs.h:3674 [inline] __fat_readdir+0x1485/0x1b40 fs/fat/dir.c:677 fat_ioctl_readdir fs/fat/dir.c:777 [inline] fat_dir_ioctl+0x27e/0x3b0 fs/fat/dir.c:815 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&sbi->s_lock){+.+.}-{3:3}: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 msdos_lookup+0xf9/0x4f0 fs/fat/namei_msdos.c:209 lookup_open fs/namei.c:3440 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x111d/0x2f20 fs/namei.c:3739 do_filp_open+0x21c/0x460 fs/namei.c:3769 do_sys_openat2+0x13b/0x500 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sb->s_type->i_mutex_key#36){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498 inode_lock_shared include/linux/fs.h:799 [inline] lookup_slow+0x45/0x70 fs/namei.c:1679 walk_component+0x48c/0x610 fs/namei.c:1976 lookup_last fs/namei.c:2431 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2455 filename_lookup+0x230/0x5c0 fs/namei.c:2484 kern_path+0x37/0x180 fs/namei.c:2582 lookup_bdev+0xc1/0x280 block/bdev.c:979 device_matched fs/btrfs/volumes.c:568 [inline] btrfs_free_stale_devices+0x71f/0xb00 fs/btrfs/volumes.c:608 btrfs_forget_devices+0x52/0x80 fs/btrfs/volumes.c:1395 btrfs_control_ioctl+0x108/0x210 fs/btrfs/super.c:2451 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#36 --> &fs_info->tree_log_mutex --> &fs_devs->device_list_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&fs_devs->device_list_mutex); lock(&fs_info->tree_log_mutex); lock(&fs_devs->device_list_mutex); lock(&sb->s_type->i_mutex_key#36); *** DEADLOCK *** 2 locks held by syz-executor.4/7837: #0: ffffffff8ce01888 (uuid_mutex){+.+.}-{3:3}, at: btrfs_forget_devices+0x1a/0x80 fs/btrfs/volumes.c:1394 #1: ffff888074bd28e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_free_stale_devices+0x14b/0xb00 fs/btrfs/volumes.c:603 stack backtrace: CPU: 1 PID: 7837 Comm: syz-executor.4 Not tainted 5.15.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498 inode_lock_shared include/linux/fs.h:799 [inline] lookup_slow+0x45/0x70 fs/namei.c:1679 walk_component+0x48c/0x610 fs/namei.c:1976 lookup_last fs/namei.c:2431 [inline] path_lookupat+0x16f/0x450 fs/namei.c:2455 filename_lookup+0x230/0x5c0 fs/namei.c:2484 kern_path+0x37/0x180 fs/namei.c:2582 lookup_bdev+0xc1/0x280 block/bdev.c:979 device_matched fs/btrfs/volumes.c:568 [inline] btrfs_free_stale_devices+0x71f/0xb00 fs/btrfs/volumes.c:608 btrfs_forget_devices+0x52/0x80 fs/btrfs/volumes.c:1395 btrfs_control_ioctl+0x108/0x210 fs/btrfs/super.c:2451 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff538cc5ee9 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:00007ff5372390c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff538df4f80 RCX: 00007ff538cc5ee9 RDX: 00000000200004c0 RSI: 0000000050009405 RDI: 0000000000000005 RBP: 00007ff538d1249e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007ff538df4f80 R15: 00007ffe4bb63108