BTRFS info (device loop0): using free space tree BTRFS info (device loop0): has skinny extents BTRFS warning (device ): duplicate device /dev/loop3 devid 1 generation 8 scanned by syz-executor.3 (23704) ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.0/23695 is trying to acquire lock: 000000006e7aa029 (&fs_info->qgroup_ioctl_lock){+.+.}, at: btrfs_limit_qgroup+0x63/0x7b0 fs/btrfs/qgroup.c:1467 but task is already holding lock: 000000007bcd468f (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] 000000007bcd468f (sb_internal#3){.+.+}, at: start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sb_internal#3){.+.+}: sb_start_intwrite include/linux/fs.h:1626 [inline] start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 btrfs_quota_enable+0x169/0x10b0 fs/btrfs/qgroup.c:905 btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:5233 [inline] btrfs_ioctl+0x622c/0x76d0 fs/btrfs/ioctl.c:6021 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&fs_info->qgroup_ioctl_lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 btrfs_limit_qgroup+0x63/0x7b0 fs/btrfs/qgroup.c:1467 btrfs_ioctl_qgroup_limit fs/btrfs/ioctl.c:5386 [inline] btrfs_ioctl+0x3c0c/0x76d0 fs/btrfs/ioctl.c:6027 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sb_internal#3); lock(&fs_info->qgroup_ioctl_lock); lock(sb_internal#3); lock(&fs_info->qgroup_ioctl_lock); *** DEADLOCK *** 2 locks held by syz-executor.0/23695: #0: 00000000eca08d5b (sb_writers#24){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 00000000eca08d5b (sb_writers#24){.+.+}, at: mnt_want_write_file+0x63/0x1d0 fs/namespace.c:418 #1: 000000007bcd468f (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] #1: 000000007bcd468f (sb_internal#3){.+.+}, at: start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 stack backtrace: CPU: 1 PID: 23695 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 btrfs_limit_qgroup+0x63/0x7b0 fs/btrfs/qgroup.c:1467 btrfs_ioctl_qgroup_limit fs/btrfs/ioctl.c:5386 [inline] btrfs_ioctl+0x3c0c/0x76d0 fs/btrfs/ioctl.c:6027 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f0d17a120c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0d15f84168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f0d17b31f80 RCX: 00007f0d17a120c9 RDX: 00000000200011c0 RSI: 000000008030942b RDI: 0000000000000005 RBP: 00007f0d17a6dae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffce75eeb1f R14: 00007f0d15f84300 R15: 0000000000022000 netlink: 600 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 296 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 296 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 600 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 296 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 296 bytes leftover after parsing attributes in process `syz-executor.1'. netlink: 600 bytes leftover after parsing attributes in process `syz-executor.2'. netlink: 296 bytes leftover after parsing attributes in process `syz-executor.2'. BTRFS warning (device ): duplicate device /dev/loop3 devid 1 generation 8 scanned by syz-executor.3 (23760) BTRFS warning (device ): duplicate device /dev/loop3 devid 1 generation 8 scanned by systemd-udevd (23798)