gfs2: fsid=syz:syz.0: first mount done, others may mount ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.49/6137 is trying to acquire lock: ffff888077658ae8 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xaf/0x670 fs/gfs2/quota.c:689 but task is already holding lock: ffff888077f1cfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1543 [inline] ffff888077f1cfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x1d80/0x2ec0 fs/gfs2/bmap.c:1867 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+0x46/0x2e0 kernel/locking/rwsem.c:1520 __gfs2_iomap_get+0x15f/0x1400 fs/gfs2/bmap.c:862 gfs2_iomap_get+0xef/0x170 fs/gfs2/bmap.c:1427 bh_get+0x251/0x760 fs/gfs2/quota.c:401 qdsb_get+0x210/0x330 fs/gfs2/quota.c:535 gfs2_quota_hold+0x198/0x5e0 fs/gfs2/quota.c:615 punch_hole+0xa3a/0x2ec0 fs/gfs2/bmap.c:1828 gfs2_iomap_end+0x5e5/0x7a0 fs/gfs2/bmap.c:1188 iomap_iter+0x21e/0xec0 fs/iomap/iter.c:79 iomap_file_buffered_write+0xbc0/0xd80 fs/iomap/buffered-io.c:999 gfs2_file_buffered_write+0x4bd/0x820 fs/gfs2/file.c:1060 gfs2_file_write_iter+0x48d/0xe90 fs/gfs2/file.c:1158 call_write_iter include/linux/fs.h:2018 [inline] aio_write+0x564/0x7d0 fs/aio.c:1593 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x73f/0x12a0 fs/aio.c:2012 __do_sys_io_submit fs/aio.c:2071 [inline] __se_sys_io_submit+0x1a1/0x310 fs/aio.c:2041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 do_qc+0xaf/0x670 fs/gfs2/quota.c:689 gfs2_quota_change+0x2b9/0x800 fs/gfs2/quota.c:1289 punch_hole+0x2902/0x2ec0 fs/gfs2/bmap.c:1968 gfs2_iomap_end+0x5e5/0x7a0 fs/gfs2/bmap.c:1188 iomap_iter+0x21e/0xec0 fs/iomap/iter.c:79 iomap_file_buffered_write+0xbc0/0xd80 fs/iomap/buffered-io.c:999 gfs2_file_buffered_write+0x4bd/0x820 fs/gfs2/file.c:1060 gfs2_file_write_iter+0x48d/0xe90 fs/gfs2/file.c:1158 call_write_iter include/linux/fs.h:2018 [inline] aio_write+0x564/0x7d0 fs/aio.c:1593 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x73f/0x12a0 fs/aio.c:2012 __do_sys_io_submit fs/aio.c:2071 [inline] __se_sys_io_submit+0x1a1/0x310 fs/aio.c:2041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 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.4.49/6137: #0: ffff888077f1cb48 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #0: ffff888077f1cb48 (&sb->s_type->i_mutex_key#24){+.+.}-{3:3}, at: gfs2_file_write_iter+0x352/0xe90 fs/gfs2/file.c:1115 #1: ffff88803010e608 (sb_internal#4){.+.+}-{0:0}, at: gfs2_trans_begin+0x6f/0xe0 fs/gfs2/trans.c:118 #2: ffff888077659060 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x517/0x890 fs/gfs2/trans.c:87 #3: ffff888077f1cfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1543 [inline] #3: ffff888077f1cfd0 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x1d80/0x2ec0 fs/gfs2/bmap.c:1867 stack backtrace: CPU: 0 PID: 6137 Comm: syz.4.49 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2df1/0x7d40 kernel/locking/lockdep.c:5137 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x136/0xcc0 kernel/locking/mutex.c:747 do_qc+0xaf/0x670 fs/gfs2/quota.c:689 gfs2_quota_change+0x2b9/0x800 fs/gfs2/quota.c:1289 punch_hole+0x2902/0x2ec0 fs/gfs2/bmap.c:1968 gfs2_iomap_end+0x5e5/0x7a0 fs/gfs2/bmap.c:1188 iomap_iter+0x21e/0xec0 fs/iomap/iter.c:79 iomap_file_buffered_write+0xbc0/0xd80 fs/iomap/buffered-io.c:999 gfs2_file_buffered_write+0x4bd/0x820 fs/gfs2/file.c:1060 gfs2_file_write_iter+0x48d/0xe90 fs/gfs2/file.c:1158 call_write_iter include/linux/fs.h:2018 [inline] aio_write+0x564/0x7d0 fs/aio.c:1593 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x73f/0x12a0 fs/aio.c:2012 __do_sys_io_submit fs/aio.c:2071 [inline] __se_sys_io_submit+0x1a1/0x310 fs/aio.c:2041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f120839c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f120920d028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007f1208615fa0 RCX: 00007f120839c799 RDX: 0000200000000540 RSI: 000000000000003b RDI: 00007f12091e4000 RBP: 00007f1208432c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1208616038 R14: 00007f1208615fa0 R15: 00007ffcf33054a8