====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.7.767/8849 is trying to acquire lock: ffff888028dccae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xca/0x730 fs/gfs2/quota.c:682 but task is already holding lock: ffff88804c484918 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] ffff88804c484918 (&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 qd_fish fs/gfs2/quota.c:485 [inline] gfs2_quota_sync+0x252/0x6f0 fs/gfs2/quota.c:1320 gfs2_sync_fs+0x48/0xb0 fs/gfs2/super.c:660 sync_filesystem+0xe6/0x220 fs/sync.c:56 generic_shutdown_super+0x6b/0x340 fs/super.c:474 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 -> #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 do_shrink+0x7a1/0x910 fs/gfs2/bmap.c:2018 gfs2_setattr_size+0x150/0x810 fs/gfs2/bmap.c:2142 gfs2_setattr+0x256/0x410 fs/gfs2/inode.c:2003 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x197/0x220 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xdc/0x190 fs/open.c:134 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 *** 5 locks held by syz.7.767/8849: #0: ffff88805bae8460 (sb_writers#39){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff88804c484480 (&sb->s_type->i_mutex_key#43){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88804c484480 (&sb->s_type->i_mutex_key#43){+.+.}-{3:3}, at: do_truncate+0x183/0x220 fs/open.c:63 #2: ffff88805bae8650 (sb_internal#7){.+.+}-{0:0}, at: gfs2_trans_begin+0x6b/0xe0 fs/gfs2/trans.c:118 #3: ffff888028dcd058 (&sdp->sd_log_flush_lock){++++}-{3:3}, at: __gfs2_trans_begin+0x50d/0x880 fs/gfs2/trans.c:87 #4: ffff88804c484918 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1512 [inline] #4: ffff88804c484918 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x241b/0x35c0 fs/gfs2/bmap.c:1837 stack backtrace: CPU: 0 PID: 8849 Comm: syz.7.767 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: 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 do_shrink+0x7a1/0x910 fs/gfs2/bmap.c:2018 gfs2_setattr_size+0x150/0x810 fs/gfs2/bmap.c:2142 gfs2_setattr+0x256/0x410 fs/gfs2/inode.c:2003 notify_change+0xc74/0xf40 fs/attr.c:499 do_truncate+0x197/0x220 fs/open.c:65 vfs_truncate+0x262/0x2f0 fs/open.c:111 do_sys_truncate+0xdc/0x190 fs/open.c:134 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: 0033:0x7f92cd18f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f92cdfc7038 EFLAGS: 00000246 ORIG_RAX: 000000000000004c RAX: ffffffffffffffda RBX: 00007f92cd3e6270 RCX: 00007f92cd18f749 RDX: 0000000000000000 RSI: 000000000000d4cb RDI: 0000200000000000 RBP: 00007f92cd213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f92cd3e6308 R14: 00007f92cd3e6270 R15: 00007ffe08d3e1d8