EXT4-fs (loop0): mounted filesystem without journal. Opts: sb=0x0000000000000001,nodioread_nolock,,errors=continue. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected 5.15.186-syzkaller #0 Not tainted ------------------------------------------------------ syz.0.1464/8108 is trying to acquire lock: ffff0000ea5b0968 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 but task is already holding lock: ffff0000d08e0278 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&ei->i_data_sem/2){++++}-{3:3}: down_write+0xbc/0x12c kernel/locking/rwsem.c:1551 ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923 ext4_quota_write+0x220/0x52c fs/ext4/super.c:6594 write_blk fs/quota/quota_tree.c:64 [inline] find_free_dqentry fs/quota/quota_tree.c:307 [inline] do_insert_tree+0xd34/0x1424 fs/quota/quota_tree.c:364 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x2c4/0x3f8 fs/quota/quota_tree.c:411 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358 dquot_acquire+0x2b0/0x510 fs/quota/dquot.c:472 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6203 dqget+0x658/0xcf4 fs/quota/dquot.c:988 __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579 ext4_mkdir+0x148/0xa40 fs/ext4/namei.c:3059 vfs_mkdir+0x314/0x4d4 fs/namei.c:4065 do_mkdirat+0x1bc/0x508 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0xc0/0x390 kernel/locking/rwsem.c:1498 v2_read_dquot+0x4c/0x118 fs/quota/quota_v2.c:332 dquot_acquire+0x120/0x510 fs/quota/dquot.c:463 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6203 dqget+0x658/0xcf4 fs/quota/dquot.c:988 __dquot_initialize+0x2d4/0xa80 fs/quota/dquot.c:1517 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579 ext4_create+0x94/0x3fc fs/ext4/namei.c:2876 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x1144/0x26e4 fs/namei.c:3739 do_filp_open+0x164/0x330 fs/namei.c:3769 do_sys_openat2+0x128/0x3d8 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x120/0x154 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #0 (&dquot->dq_lock){+.+.}-{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+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6183 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6260 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x1f8/0x424 fs/quota/dquot.c:412 __dquot_alloc_space+0x560/0xd0c fs/quota/dquot.c:1752 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline] dquot_alloc_space include/linux/quotaops.h:310 [inline] dquot_alloc_block include/linux/quotaops.h:334 [inline] ext4_mb_new_blocks+0xd30/0x4024 fs/ext4/mballoc.c:5739 ext4_ext_map_blocks+0xf74/0x562c fs/ext4/extents.c:4341 ext4_map_blocks+0x7b8/0x167c fs/ext4/inode.c:673 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923 ext4_append+0x238/0x474 fs/ext4/namei.c:83 ext4_init_new_dir+0x258/0x864 fs/ext4/namei.c:3030 ext4_mkdir+0x3c0/0xa40 fs/ext4/namei.c:3076 vfs_mkdir+0x314/0x4d4 fs/namei.c:4065 do_mkdirat+0x1bc/0x508 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 other info that might help us debug this: Chain exists of: &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&ei->i_data_sem/2); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); lock(&dquot->dq_lock); *** DEADLOCK *** 4 locks held by syz.0.1464/8108: #0: ffff0000c15d6460 (sb_writers#3){++++}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:377 #1: ffff0000d08ebfc0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:822 [inline] #1: ffff0000d08ebfc0 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x1ac/0x39c fs/namei.c:3835 #2: ffff0000d08e0278 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 #3: ffff8000144487d8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 stack backtrace: CPU: 1 PID: 8108 Comm: syz.0.1464 Not tainted 5.15.186-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2011 check_noncircular+0x240/0x2d4 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+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6183 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6260 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x1f8/0x424 fs/quota/dquot.c:412 __dquot_alloc_space+0x560/0xd0c fs/quota/dquot.c:1752 dquot_alloc_space_nodirty include/linux/quotaops.h:297 [inline] dquot_alloc_space include/linux/quotaops.h:310 [inline] dquot_alloc_block include/linux/quotaops.h:334 [inline] ext4_mb_new_blocks+0xd30/0x4024 fs/ext4/mballoc.c:5739 ext4_ext_map_blocks+0xf74/0x562c fs/ext4/extents.c:4341 ext4_map_blocks+0x7b8/0x167c fs/ext4/inode.c:673 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923 ext4_append+0x238/0x474 fs/ext4/namei.c:83 ext4_init_new_dir+0x258/0x864 fs/ext4/namei.c:3030 ext4_mkdir+0x3c0/0xa40 fs/ext4/namei.c:3076 vfs_mkdir+0x314/0x4d4 fs/namei.c:4065 do_mkdirat+0x1bc/0x508 fs/namei.c:4090 __do_sys_mkdirat fs/namei.c:4105 [inline] __se_sys_mkdirat fs/namei.c:4103 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4103 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 EXT4-fs error (device loop0): ext4_empty_dir:3136: inode #12: comm syz.0.1464: invalid size