gfs2: fsid=syz:syz.0: found 1 quota changes ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.88/4745 is trying to acquire lock: ffff8880274c4ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xca/0x730 fs/gfs2/quota.c:678 but task is already holding lock: ffff88805fef5080 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1514 [inline] ffff88805fef5080 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x24ed/0x37a0 fs/gfs2/bmap.c:1839 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+0x44/0x2e0 kernel/locking/rwsem.c:1498 __gfs2_iomap_get+0x15b/0x1400 fs/gfs2/bmap.c:858 gfs2_iomap_get fs/gfs2/bmap.c:1398 [inline] gfs2_block_map+0x2a0/0x740 fs/gfs2/bmap.c:1213 bh_get+0x275/0x650 fs/gfs2/quota.c:385 qdsb_get+0x21c/0x3c0 fs/gfs2/quota.c:518 gfs2_quota_hold+0x194/0x5d0 fs/gfs2/quota.c:604 punch_hole+0xddb/0x37a0 fs/gfs2/bmap.c:1800 gfs2_iomap_end+0x4f2/0x6b0 fs/gfs2/bmap.c:1159 iomap_iter+0x22a/0xdb0 fs/iomap/iter.c:62 iomap_file_buffered_write+0x520/0x630 fs/iomap/buffered-io.c:814 gfs2_file_buffered_write+0x470/0x900 fs/gfs2/file.c:1058 gfs2_file_write_iter+0xfaf/0x1240 fs/gfs2/file.c:1145 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 do_qc+0xca/0x730 fs/gfs2/quota.c:678 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 punch_hole+0x31d2/0x37a0 fs/gfs2/bmap.c:1940 gfs2_iomap_end+0x4f2/0x6b0 fs/gfs2/bmap.c:1159 iomap_iter+0x22a/0xdb0 fs/iomap/iter.c:62 iomap_file_buffered_write+0x520/0x630 fs/iomap/buffered-io.c:814 gfs2_file_buffered_write+0x470/0x900 fs/gfs2/file.c:1058 gfs2_file_write_iter+0xfaf/0x1240 fs/gfs2/file.c:1145 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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 *** 6 locks held by syz.2.88/4745: #0: ffff8880250440f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1056 #1: ffff8880773ae460 (sb_writers#20){.+.+}-{0:0}, at: vfs_write+0x295/0xd60 fs/read_write.c:590 #2: ffff88805fef4be8 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #2: ffff88805fef4be8 (&sb->s_type->i_mutex_key#25){+.+.}-{3:3}, at: gfs2_file_write_iter+0x35e/0x1240 fs/gfs2/file.c:1123 #3: ffff8880773ae650 (sb_internal#5){.+.+}-{0:0}, at: gfs2_trans_begin+0x6b/0xe0 fs/gfs2/trans.c:118 #4: ffff8880274c50a8 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x515/0x890 fs/gfs2/trans.c:87 #5: ffff88805fef5080 (&ip->i_rw_mutex){++++}-{3:3}, at: sweep_bh_for_rgrps fs/gfs2/bmap.c:1514 [inline] #5: ffff88805fef5080 (&ip->i_rw_mutex){++++}-{3:3}, at: punch_hole+0x24ed/0x37a0 fs/gfs2/bmap.c:1839 stack backtrace: CPU: 1 PID: 4745 Comm: syz.2.88 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 do_qc+0xca/0x730 fs/gfs2/quota.c:678 gfs2_quota_change+0x2f5/0x8e0 fs/gfs2/quota.c:1295 punch_hole+0x31d2/0x37a0 fs/gfs2/bmap.c:1940 gfs2_iomap_end+0x4f2/0x6b0 fs/gfs2/bmap.c:1159 iomap_iter+0x22a/0xdb0 fs/iomap/iter.c:62 iomap_file_buffered_write+0x520/0x630 fs/iomap/buffered-io.c:814 gfs2_file_buffered_write+0x470/0x900 fs/gfs2/file.c:1058 gfs2_file_write_iter+0xfaf/0x1240 fs/gfs2/file.c:1145 call_write_iter include/linux/fs.h:2173 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x745/0xd60 fs/read_write.c:594 ksys_write+0x152/0x260 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbcf6e3beb9 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:00007fbcf5097028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fbcf70b6fa0 RCX: 00007fbcf6e3beb9 RDX: 0000000000806000 RSI: 0000200000000200 RDI: 0000000000000007 RBP: 00007fbcf6ea9c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbcf70b7038 R14: 00007fbcf70b6fa0 R15: 00007fff5e12f608