BTRFS info (device loop1): has skinny extents audit: type=1800 audit(1670499985.637:370): pid=29009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.1" name=".pending_reads" dev="loop1" ino=263 res=0 ====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/29009 is trying to acquire lock: 00000000309cdf67 (&fs_info->qgroup_ioctl_lock){+.+.}, at: btrfs_del_qgroup_relation+0x45/0x70 fs/btrfs/qgroup.c:1366 but task is already holding lock: 0000000068b5a5e8 (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] 0000000068b5a5e8 (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_del_qgroup_relation+0x45/0x70 fs/btrfs/qgroup.c:1366 btrfs_ioctl_qgroup_assign fs/btrfs/ioctl.c:5282 [inline] btrfs_ioctl+0x6004/0x76d0 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 BTRFS: device fsid a6a605fc-d5f1-4e66-8595-3726e2b761d6 devid 1 transid 8 /dev/loop4 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.1/29009: #0: 0000000091969e4c (sb_writers#22){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline] #0: 0000000091969e4c (sb_writers#22){.+.+}, at: mnt_want_write_file+0x63/0x1d0 fs/namespace.c:418 #1: 0000000068b5a5e8 (sb_internal#3){.+.+}, at: sb_start_intwrite include/linux/fs.h:1626 [inline] #1: 0000000068b5a5e8 (sb_internal#3){.+.+}, at: start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 stack backtrace: CPU: 0 PID: 29009 Comm: syz-executor.1 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_del_qgroup_relation+0x45/0x70 fs/btrfs/qgroup.c:1366 btrfs_ioctl_qgroup_assign fs/btrfs/ioctl.c:5282 [inline] btrfs_ioctl+0x6004/0x76d0 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: 0033:0x7f111c3f10d9 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:00007f111a963168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f111c510f80 RCX: 00007f111c3f10d9 RDX: 0000000020000280 RSI: 0000000040189429 RDI: 0000000000000004 RBP: 00007f111c44cae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffed98ff41f R14: 00007f111a963300 R15: 0000000000022000 BTRFS error (device loop1): fail to start transaction for status update: -28 BTRFS error (device loop4): unsupported checksum algorithm 3 BTRFS error (device loop4): superblock checksum mismatch IPVS: ftp: loaded support on port[0] = 21 BTRFS error (device loop4): open_ctree failed netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. IPVS: ftp: loaded support on port[0] = 21 netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect caif:caif_disconnect_client(): nothing to disconnect serio: Serial port pts0 caif:caif_disconnect_client(): nothing to disconnect EXT4-fs (loop3): Unsupported blocksize for fs encryption caif:caif_disconnect_client(): nothing to disconnect IPVS: ftp: loaded support on port[0] = 21 serio: Serial port pts0 caif:caif_disconnect_client(): nothing to disconnect EXT4-fs (loop3): Unsupported blocksize for fs encryption caif:caif_disconnect_client(): nothing to disconnect serio: Serial port pts0 serio: Serial port pts0 IPVS: ftp: loaded support on port[0] = 21 EXT4-fs (loop3): Unsupported blocksize for fs encryption EXT4-fs (loop3): Unsupported blocksize for fs encryption IPVS: ftp: loaded support on port[0] = 21