System zones: 0-5 EXT4-fs (loop4): mounted filesystem without journal. Opts: debug,jqfmt=vfsv0,inlinecrypt,debug,test_dummy_encryption=v1,norecovery,delalloc,nogrpid,minixdf,,errors=continue. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.479/6096 is trying to acquire lock: ffff88805e53e628 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x350/0x1a50 fs/ext4/inode.c:600 but task is already holding lock: ffff88807c158208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354 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+0x44/0x2e0 kernel/locking/rwsem.c:1498 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:332 dquot_acquire+0x152/0x520 fs/quota/dquot.c:488 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232 dqget+0x713/0xbb0 fs/quota/dquot.c:1010 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1539 ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0xad8/0x1320 fs/ext4/orphan.c:472 ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006 mount_bdev+0x28a/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x247/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 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 -> #1 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 dquot_commit+0x5a/0x410 fs/quota/dquot.c:532 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:437 __dquot_free_space+0x7c3/0xb80 fs/quota/dquot.c:1964 dquot_free_space_nodirty include/linux/quotaops.h:369 [inline] dquot_free_space include/linux/quotaops.h:374 [inline] dquot_free_block include/linux/quotaops.h:385 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline] ext4_free_blocks+0x1b1b/0x24c0 fs/ext4/mballoc.c:6294 ext4_remove_blocks fs/ext4/extents.c:2540 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2706 [inline] ext4_ext_remove_space+0x2106/0x41a0 fs/ext4/extents.c:2954 ext4_ext_truncate+0x182/0x230 fs/ext4/extents.c:4504 ext4_truncate+0xa41/0x1190 fs/ext4/inode.c:4263 ext4_setattr+0x117c/0x1b70 fs/ext4/inode.c:5620 notify_change+0xbc6/0xee0 fs/attr.c:505 do_truncate+0x1ac/0x240 fs/open.c:65 handle_truncate fs/namei.c:3273 [inline] do_open fs/namei.c:3620 [inline] path_openat+0x293b/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_open fs/open.c:1279 [inline] __se_sys_open fs/open.c:1275 [inline] __x64_sys_open+0x11b/0x140 fs/open.c:1275 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 (&ei->i_data_sem/2){++++}-{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+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x350/0x1a50 fs/ext4/inode.c:600 ext4_getblk+0x176/0x670 fs/ext4/inode.c:872 ext4_bread+0x26/0x180 fs/ext4/inode.c:925 ext4_quota_write+0x237/0x580 fs/ext4/super.c:6623 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x38a/0x7a0 fs/quota/quota_tree.c:125 do_insert_tree+0x21b/0x19c0 fs/quota/quota_tree.c:335 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x354/0x4a0 fs/quota/quota_tree.c:411 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:497 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232 dqget+0x713/0xbb0 fs/quota/dquot.c:1010 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1539 ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_open fs/open.c:1279 [inline] __se_sys_open fs/open.c:1275 [inline] __x64_sys_open+0x11b/0x140 fs/open.c:1275 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: 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 *** 3 locks held by syz.4.479/6096: #0: ffff88807c158460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff88805e71c0a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:485 #2: ffff88807c158208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354 stack backtrace: CPU: 0 PID: 6096 Comm: syz.4.479 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x350/0x1a50 fs/ext4/inode.c:600 ext4_getblk+0x176/0x670 fs/ext4/inode.c:872 ext4_bread+0x26/0x180 fs/ext4/inode.c:925 ext4_quota_write+0x237/0x580 fs/ext4/super.c:6623 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x38a/0x7a0 fs/quota/quota_tree.c:125 do_insert_tree+0x21b/0x19c0 fs/quota/quota_tree.c:335 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x354/0x4a0 fs/quota/quota_tree.c:411 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:497 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232 dqget+0x713/0xbb0 fs/quota/dquot.c:1010 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1539 ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_open fs/open.c:1279 [inline] __se_sys_open fs/open.c:1275 [inline] __x64_sys_open+0x11b/0x140 fs/open.c:1275 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: 0033:0x7f6d17fe70d9 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:00007f6d1623f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f6d1826efa0 RCX: 00007f6d17fe70d9 RDX: 0000000000000020 RSI: 000000000004827e RDI: 0000200000000200 RBP: 00007f6d1807e024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6d1826f038 R14: 00007f6d1826efa0 R15: 00007ffd215e5f18