audit: type=1800 audit(1671475619.790:624): pid=18262 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="loop5" ino=263 res=0 ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.5/18262 is trying to acquire lock: 00000000a29b71a2 (&fs_info->qgroup_ioctl_lock){+.+.}, at: btrfs_add_qgroup_relation+0xa7/0x740 fs/btrfs/qgroup.c:1264 but task is already holding lock: 0000000023a92bc3 (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] 0000000023a92bc3 (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){+.+.}: audit: type=1804 audit(1671475619.830:625): pid=18262 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir2085957550/syzkaller.biS8vz/1027/file0/bus" dev="loop5" ino=263 res=1 __mutex_lock_common kernel/locking/mutex.c:937 [inline] __mutex_lock+0xd7/0x1190 kernel/locking/mutex.c:1078 btrfs_add_qgroup_relation+0xa7/0x740 fs/btrfs/qgroup.c:1264 btrfs_ioctl_qgroup_assign fs/btrfs/ioctl.c:5280 [inline] btrfs_ioctl+0x3a05/0x76d0 fs/btrfs/ioctl.c:6023 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.5/18262: #0: 000000006ea56d16 (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 000000006ea56d16 (sb_writers#19){.+.+}, at: mnt_want_write_file+0x63/0x1d0 fs/namespace.c:418 #1: 0000000023a92bc3 (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] #1: 0000000023a92bc3 (sb_internal#3){.+.+}, at: start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 stack backtrace: CPU: 1 PID: 18262 Comm: syz-executor.5 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_add_qgroup_relation+0xa7/0x740 fs/btrfs/qgroup.c:1264 btrfs_ioctl_qgroup_assign fs/btrfs/ioctl.c:5280 [inline] btrfs_ioctl+0x3a05/0x76d0 fs/btrfs/ioctl.c:6023 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: 0033:0x7ff2e49250d9 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:00007ff2e2e97168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ff2e4a44f80 RCX: 00007ff2e49250d9 RDX: 00000000200010c0 RSI: 0000000040189429 RDI: 0000000000000005 RBP: 00007ff2e4980ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe9b4edcdf R14: 00007ff2e2e97300 R15: 0000000000022000 BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents audit: type=1800 audit(1671475621.190:626): pid=18370 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="loop5" ino=263 res=0 audit: type=1804 audit(1671475621.210:627): pid=18370 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir2085957550/syzkaller.biS8vz/1028/file0/bus" dev="loop5" ino=263 res=1 audit: type=1800 audit(1671475621.560:628): pid=18453 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.5" name="bus" dev="sda1" ino=15123 res=0 audit: type=1804 audit(1671475621.610:629): pid=18453 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir2085957550/syzkaller.biS8vz/1029/bus" dev="sda1" ino=15123 res=1 BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents