EXT4-fs: Warning: mounting with an experimental mount option 'dioread_nolock' for blocksize < PAGE_SIZE EXT4-fs (loop2): mounted filesystem without journal. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.283/6444 is trying to acquire lock: ffff0000f5b34428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x1c8 fs/quota/dquot.c:532 but task is already holding lock: ffff0000e1b2e6d8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x720/0x160c fs/ext4/inode.c:674 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_read+0x64/0x300 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x270/0x160c fs/ext4/inode.c:606 ext4_getblk+0x178/0x680 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_quota_read+0x160/0x358 fs/ext4/super.c:7182 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x178/0xc2c fs/quota/quota_tree.c:671 find_tree_dqentry+0x4fc/0xc2c fs/quota/quota_tree.c:698 find_tree_dqentry+0x4fc/0xc2c fs/quota/quota_tree.c:698 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x45c/0x748 fs/quota/quota_tree.c:736 v2_read_dquot+0xbc/0x118 fs/quota/quota_v2.c:336 dquot_acquire+0x108/0x4b8 fs/quota/dquot.c:488 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1010 __dquot_initialize+0x280/0xb30 fs/quota/dquot.c:1539 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1601 ext4_process_orphan+0x5c/0x2c0 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0x964/0x1090 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x5af8/0x63bc fs/ext4/super.c:5693 get_tree_bdev+0x35c/0x54c fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5723 vfs_get_tree+0x90/0x278 fs/super.c:1573 do_new_mount+0x228/0x804 fs/namespace.c:3078 path_mount+0x5ac/0xe6c fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x4a0/0x5a0 fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x64/0x300 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4c/0x118 fs/quota/quota_v2.c:335 dquot_acquire+0x108/0x4b8 fs/quota/dquot.c:488 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1010 __dquot_initialize+0x280/0xb30 fs/quota/dquot.c:1539 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1601 ext4_process_orphan+0x5c/0x2c0 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0x964/0x1090 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x5af8/0x63bc fs/ext4/super.c:5693 get_tree_bdev+0x35c/0x54c fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5723 vfs_get_tree+0x90/0x278 fs/super.c:1573 do_new_mount+0x228/0x804 fs/namespace.c:3078 path_mount+0x5ac/0xe6c fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x4a0/0x5a0 fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 -> #0 (&dquot->dq_lock){+.+.}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x27c8/0x6610 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 dquot_commit+0x54/0x1c8 fs/quota/dquot.c:532 ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817 ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:437 __dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1774 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+0xd40/0x4244 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x1330/0x563c fs/ext4/extents.c:4361 ext4_map_blocks+0x7b0/0x160c fs/ext4/inode.c:681 _ext4_get_block+0x198/0x4dc fs/ext4/inode.c:824 ext4_get_block_unwritten+0x3c/0x110 fs/ext4/inode.c:857 ext4_block_write_begin+0x52c/0x10d8 fs/ext4/inode.c:1126 ext4_write_begin+0x5e8/0x12d4 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x24c/0x994 fs/ext4/inode.c:3002 generic_perform_write+0x240/0x508 mm/filemap.c:3862 ext4_buffered_write_iter+0x2c0/0x520 fs/ext4/file.c:285 ext4_file_write_iter+0x188/0x1500 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 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 *** 5 locks held by syz.2.283/6444: #0: ffff0000faaf1268 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x118/0x17c fs/file.c:1038 #1: ffff0000f68ee460 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x254/0x7c8 fs/read_write.c:580 #2: ffff0000e1b2e850 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #2: ffff0000e1b2e850 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: ext4_buffered_write_iter+0x94/0x520 fs/ext4/file.c:279 #3: ffff0000e1b2e6d8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x720/0x160c fs/ext4/inode.c:674 #4: ffff80001563c968 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 6444 Comm: syz.2.283 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:158 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2048 check_noncircular+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x27c8/0x6610 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x1a0/0x1f3c kernel/locking/mutex.c:603 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799 dquot_commit+0x54/0x1c8 fs/quota/dquot.c:532 ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817 ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:437 __dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1774 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+0xd40/0x4244 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x1330/0x563c fs/ext4/extents.c:4361 ext4_map_blocks+0x7b0/0x160c fs/ext4/inode.c:681 _ext4_get_block+0x198/0x4dc fs/ext4/inode.c:824 ext4_get_block_unwritten+0x3c/0x110 fs/ext4/inode.c:857 ext4_block_write_begin+0x52c/0x10d8 fs/ext4/inode.c:1126 ext4_write_begin+0x5e8/0x12d4 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x24c/0x994 fs/ext4/inode.c:3002 generic_perform_write+0x240/0x508 mm/filemap.c:3862 ext4_buffered_write_iter+0x2c0/0x520 fs/ext4/file.c:285 ext4_file_write_iter+0x188/0x1500 fs/ext4/file.c:-1 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x3c8/0x7c8 fs/read_write.c:584 ksys_write+0x12c/0x228 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __arm64_sys_write+0x7c/0x90 fs/read_write.c:646 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 EXT4-fs error (device loop2): __ext4_get_inode_loc:4520: comm syz.2.283: Invalid inode table block 3287424312 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5952: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6156: inode #18: comm syz.2.283: mark_inode_dirty error EXT4-fs error (device loop2): ext4_read_block_bitmap_nowait:477: comm syz.2.283: Invalid block bitmap block 2111649195 in block_group 0 EXT4-fs error (device loop2): __ext4_get_inode_loc:4520: comm syz.2.283: Invalid inode table block 3287424312 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5952: Corrupt filesystem EXT4-fs error (device loop2): ext4_dirty_inode:6156: inode #18: comm syz.2.283: mark_inode_dirty error EXT4-fs error (device loop2): __ext4_get_inode_loc:4520: comm syz.2.283: Invalid inode table block 3287424312 in block_group 0 EXT4-fs error (device loop2) in ext4_reserve_inode_write:5952: Corrupt filesystem EXT4-fs error (device loop2): ext4_ext_truncate:4475: inode #18: comm syz.2.283: mark_inode_dirty error