EXT4-fs (loop4): mounted filesystem without journal. Quota mode: writeback. ext4 filesystem being mounted at /227/file1 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.1049/7176 is trying to acquire lock: ffff888055ffdcd0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 but task is already holding lock: ffff888142b34208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:357 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 dquot_acquire+0x152/0x520 fs/quota/dquot.c:491 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6844 dqget+0x713/0xbb0 fs/quota/dquot.c:1013 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1542 ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0xdfe/0x1650 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5578 [inline] ext4_fill_super+0x6cd4/0x77b0 fs/ext4/super.c:5700 get_tree_bdev+0x3e6/0x610 fs/super.c:1377 vfs_get_tree+0x88/0x270 fs/super.c:1584 do_new_mount+0x247/0xa50 fs/namespace.c:3104 do_mount fs/namespace.c:3475 [inline] __do_sys_mount fs/namespace.c:3683 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3660 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xb40 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:535 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6824 mark_dquot_dirty fs/quota/dquot.c:400 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440 __dquot_alloc_space+0x5f6/0xe50 fs/quota/dquot.c:1777 dquot_alloc_space_nodirty include/linux/quotaops.h:293 [inline] dquot_alloc_space include/linux/quotaops.h:306 [inline] dquot_alloc_block include/linux/quotaops.h:330 [inline] ext4_mb_new_blocks+0xf55/0x44d0 fs/ext4/mballoc.c:5755 ext4_ext_map_blocks+0x184a/0x6680 fs/ext4/extents.c:4369 ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681 _ext4_get_block+0x1e7/0x540 fs/ext4/inode.c:824 ext4_block_write_begin+0x63b/0x12f0 fs/ext4/inode.c:1126 ext4_write_begin+0x623/0xf40 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x408/0x920 fs/ext4/inode.c:3005 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862 ext4_buffered_write_iter+0x11a/0x380 fs/ext4/file.c:292 ext4_file_write_iter+0x1e3/0x17d0 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2271 [inline] aio_write+0x545/0x780 fs/aio.c:1615 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x6ea/0x1340 fs/aio.c:2034 __do_sys_io_submit fs/aio.c:2093 [inline] __se_sys_io_submit+0x19d/0x310 fs/aio.c:2063 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->i_data_sem/2){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790 down_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_quota_write+0x237/0x580 fs/ext4/super.c:7223 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x68c/0xc30 fs/quota/quota_tree.c:318 do_insert_tree+0x717/0x1060 fs/quota/quota_tree.c:400 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49b/0x5d0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:500 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6844 dqget+0x713/0xbb0 fs/quota/dquot.c:1013 __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1542 ext4_rmdir+0x146/0xb70 fs/ext4/namei.c:3203 vfs_rmdir+0x34e/0x4a0 fs/namei.c:4246 do_rmdir+0x29a/0x5c0 fs/namei.c:4307 __do_sys_rmdir fs/namei.c:4326 [inline] __se_sys_rmdir fs/namei.c:4324 [inline] __x64_sys_rmdir+0x45/0x50 fs/namei.c:4324 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Chain exists of: &ei->i_data_sem/2 --> &dquot->dq_lock --> &s->s_dquot.dqio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&s->s_dquot.dqio_sem); lock(&dquot->dq_lock); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); *** DEADLOCK *** 5 locks held by syz.4.1049/7176: #0: ffff888142b34460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff888055ffac20 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:799 [inline] #1: ffff888055ffac20 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_rmdir+0x1b7/0x5c0 fs/namei.c:4294 #2: ffff888055ffa218 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline] #2: ffff888055ffa218 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_rmdir+0xea/0x4a0 fs/namei.c:4235 #3: ffff888052cc85e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:488 #4: ffff888142b34208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:357 stack backtrace: CPU: 1 PID: 7176 Comm: syz.4.1049 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2215 check_prev_add kernel/locking/lockdep.c:3162 [inline] check_prevs_add kernel/locking/lockdep.c:3281 [inline] validate_chain kernel/locking/lockdep.c:3897 [inline] __lock_acquire+0x3a03/0x7ea0 kernel/locking/lockdep.c:5171 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790 down_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_quota_write+0x237/0x580 fs/ext4/super.c:7223 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x68c/0xc30 fs/quota/quota_tree.c:318 do_insert_tree+0x717/0x1060 fs/quota/quota_tree.c:400 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49b/0x5d0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:500 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6844 dqget+0x713/0xbb0 fs/quota/dquot.c:1013 __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1542 ext4_rmdir+0x146/0xb70 fs/ext4/namei.c:3203 vfs_rmdir+0x34e/0x4a0 fs/namei.c:4246 do_rmdir+0x29a/0x5c0 fs/namei.c:4307 __do_sys_rmdir fs/namei.c:4326 [inline] __se_sys_rmdir fs/namei.c:4324 [inline] __x64_sys_rmdir+0x45/0x50 fs/namei.c:4324 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc61dfa94d9 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:00007fc61ee46028 EFLAGS: 00000246 ORIG_RAX: 0000000000000054 RAX: ffffffffffffffda RBX: 00007fc61e225fa0 RCX: 00007fc61dfa94d9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000b80 RBP: 00007fc61e03804e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc61e226038 R14: 00007fc61e225fa0 R15: 00007ffd1fc4b738 EXT4-fs error (device loop4): ext4_empty_dir:3138: inode #12: comm syz.4.1049: invalid size EXT4-fs (loop4): Remounting filesystem read-only EXT4-fs (loop4): unmounting filesystem.