syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/4282 is trying to acquire lock:
ffff888073dc4ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xca/0x730 fs/gfs2/quota.c:682

but task is already holding lock:
ffff88804ecccfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline]
ffff88804ecccfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x241b/0x35c0 fs/gfs2/bmap.c:1837

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ip->i_rw_mutex){++++}-{3:3}:
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       __gfs2_iomap_get+0x155/0x13e0 fs/gfs2/bmap.c:856
       gfs2_iomap_get+0xc1/0x120 fs/gfs2/bmap.c:1396
       bh_get+0x241/0x730 fs/gfs2/quota.c:385
       qdsb_get+0x21c/0x3c0 fs/gfs2/quota.c:522
       gfs2_quota_hold+0x194/0x5d0 fs/gfs2/quota.c:608
       punch_hole+0xd16/0x35c0 fs/gfs2/bmap.c:1798
       evict_unlinked_inode+0x1a3/0x6d0 fs/gfs2/super.c:1398
       gfs2_evict_inode+0x6a7/0x1170 fs/gfs2/super.c:1497
       evict+0x485/0x870 fs/inode.c:705
       do_unlinkat+0x377/0x560 fs/namei.c:4405
       __do_sys_unlink fs/namei.c:4446 [inline]
       __se_sys_unlink fs/namei.c:4444 [inline]
       __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
       do_qc+0xca/0x730 fs/gfs2/quota.c:682
       gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295
       punch_hole+0x304c/0x35c0 fs/gfs2/bmap.c:1938
       evict_unlinked_inode+0x1a3/0x6d0 fs/gfs2/super.c:1398
       gfs2_evict_inode+0x6a7/0x1170 fs/gfs2/super.c:1497
       evict+0x485/0x870 fs/inode.c:705
       do_unlinkat+0x377/0x560 fs/namei.c:4405
       __do_sys_unlink fs/namei.c:4446 [inline]
       __se_sys_unlink fs/namei.c:4444 [inline]
       __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ip->i_rw_mutex);
                               lock(&sdp->sd_quota_mutex);
                               lock(&ip->i_rw_mutex);
  lock(&sdp->sd_quota_mutex);

 *** DEADLOCK ***

4 locks held by syz-executor/4282:
 #0: ffff888058256460
 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402
 #1: ffff888058256650 (sb_internal#6){.+.+}-{0:0}, at: gfs2_trans_begin+0x6b/0xe0 fs/gfs2/trans.c:118
 #2: ffff888073dc5058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x50d/0x880 fs/gfs2/trans.c:87
 #3: ffff88804ecccfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline]
 #3: ffff88804ecccfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x241b/0x35c0 fs/gfs2/bmap.c:1837

stack backtrace:
CPU: 0 PID: 4282 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
 do_qc+0xca/0x730 fs/gfs2/quota.c:682
 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295
 punch_hole+0x304c/0x35c0 fs/gfs2/bmap.c:1938
 evict_unlinked_inode+0x1a3/0x6d0 fs/gfs2/super.c:1398
 gfs2_evict_inode+0x6a7/0x1170 fs/gfs2/super.c:1497
 evict+0x485/0x870 fs/inode.c:705
 do_unlinkat+0x377/0x560 fs/namei.c:4405
 __do_sys_unlink fs/namei.c:4446 [inline]
 __se_sys_unlink fs/namei.c:4444 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f126358ecf7
Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffff2348288 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f126358ecf7
RDX: 00007ffff23482b0 RSI: 00007ffff2348340 RDI: 00007ffff2348340
RBP: 00007ffff2348340 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffff2349430
R13: 00007f1263613d7d R14: 0000000000024882 R15: 00007ffff234a500
 </TASK>
syz-executor: attempt to access beyond end of device
loop4: rw=1, sector=2972, nr_sectors = 14 limit=64
gfs2: fsid=syz:syz.0: Error 10 writing to journal, jid=0
gfs2: fsid=syz:syz.0: about to withdraw this file system
gfs2: fsid=syz:syz.0: Journal recovery skipped for jid 0 until next mount.
gfs2: fsid=syz:syz.0: Glock dequeues delayed: 0
gfs2: fsid=syz:syz.0: File system withdrawn
CPU: 0 PID: 4282 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 gfs2_withdraw+0x143f/0x1780 fs/gfs2/util.c:366
 gfs2_log_flush+0x1d7b/0x24e0 fs/gfs2/log.c:1156
 gfs2_kill_sb+0x50/0xd0 fs/gfs2/ops_fstype.c:1729
 deactivate_locked_super+0x93/0xf0 fs/super.c:332
 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1191
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1263590a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffff2348288 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007f1263590a77
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffff2349430
RBP: 00007f1263613d7d R08: 000055558c37c663 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffff2349430
R13: 00007f1263613d7d R14: 000055558c3614a8 R15: 00007ffff234a500
 </TASK>
gfs2: fsid=syz:syz.0: warning: assertion "!qd->qd_change" failed at function = gfs2_quota_cleanup, file = fs/gfs2/quota.c, line = 1485
CPU: 0 PID: 4282 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 gfs2_assert_warn_i+0x18f/0x2c0 fs/gfs2/util.c:427
 gfs2_quota_cleanup+0x4b4/0x6a0 fs/gfs2/quota.c:1485
 gfs2_put_super+0x22f/0x8c0 fs/gfs2/super.c:601
 generic_shutdown_super+0x130/0x340 fs/super.c:501
 kill_block_super+0x7c/0xe0 fs/super.c:1470
 deactivate_locked_super+0x93/0xf0 fs/super.c:332
 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1191
 task_work_run+0x1ca/0x250 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f1263590a77
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffff2348288 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007f1263590a77
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffff2349430
RBP: 00007f1263613d7d R08: 000055558c37c663 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffff2349430
R13: 00007f1263613d7d R14: 000055558c3614a8 R15: 00007ffff234a500
 </TASK>