EXT4-fs: Ignoring removed oldalloc option EXT4-fs (loop2): mounted filesystem without journal. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.575/5880 is trying to acquire lock: ffff0000f9881698 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x278/0x1778 fs/ext4/inode.c:606 but task is already holding lock: ffff0000ce834208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 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+0x64/0x300 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4c/0x118 fs/quota/quota_v2.c:335 dquot_acquire+0x120/0x4d8 fs/quota/dquot.c:463 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6837 dqget+0x654/0xcc4 fs/quota/dquot.c:988 __dquot_initialize+0x2fc/0xacc fs/quota/dquot.c:1517 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579 ext4_process_orphan+0x5c/0x2b4 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0x920/0x1060 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x594c/0x61b0 fs/ext4/super.c:5693 get_tree_bdev+0x358/0x544 fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5723 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5bc/0xe80 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+0x49c/0x59c fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 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 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common+0x190/0x1f60 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+0x50/0x1c4 fs/quota/dquot.c:507 ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6817 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6894 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412 __dquot_alloc_space+0x560/0xce0 fs/quota/dquot.c:1752 dquot_alloc_space_nodirty include/linux/quotaops.h:300 [inline] dquot_alloc_space include/linux/quotaops.h:313 [inline] dquot_alloc_block include/linux/quotaops.h:337 [inline] ext4_mb_new_blocks+0xd38/0x4254 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x1394/0x56f4 fs/ext4/extents.c:4346 ext4_map_blocks+0x860/0x1778 fs/ext4/inode.c:681 _ext4_get_block+0x19c/0x4d8 fs/ext4/inode.c:824 ext4_get_block_unwritten+0x3c/0x110 fs/ext4/inode.c:857 ext4_block_write_begin+0x50c/0x10e4 fs/ext4/inode.c:1126 ext4_write_begin+0x5f4/0x131c fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x348/0x990 fs/ext4/inode.c:3002 generic_perform_write+0x234/0x4f4 mm/filemap.c:3862 ext4_buffered_write_iter+0x2c4/0x528 fs/ext4/file.c:285 ext4_file_write_iter+0x18c/0x1574 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+0x3ec/0x7f0 fs/read_write.c:584 ksys_write+0x12c/0x224 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+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 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 (&ei->i_data_sem/2){++++}-{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+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 down_read+0x64/0x300 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x278/0x1778 fs/ext4/inode.c:606 ext4_getblk+0x178/0x664 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_quota_write+0x204/0x534 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x284/0x574 fs/quota/quota_tree.c:136 do_insert_tree+0x1c4/0xc34 fs/quota/quota_tree.c:347 do_insert_tree+0x790/0xc34 fs/quota/quota_tree.c:402 do_insert_tree+0x764/0xc34 fs/quota/quota_tree.c:402 do_insert_tree+0x764/0xc34 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x3d4/0x4f0 fs/quota/quota_tree.c:451 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:361 dquot_acquire+0x2a8/0x4d8 fs/quota/dquot.c:472 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6837 dqget+0x654/0xcc4 fs/quota/dquot.c:988 dquot_transfer+0x314/0x708 fs/quota/dquot.c:2150 ext4_setattr+0x7d4/0x15f0 fs/ext4/inode.c:5527 notify_change+0xb0c/0xdcc fs/attr.c:499 chown_common+0x420/0x594 fs/open.c:736 vfs_fchown fs/open.c:804 [inline] ksys_fchown+0xe0/0x158 fs/open.c:815 __do_sys_fchown fs/open.c:823 [inline] __se_sys_fchown fs/open.c:821 [inline] __arm64_sys_fchown+0x7c/0x94 fs/open.c:821 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 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: &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.2.575/5880: #0: ffff0000ce834460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write_file+0x64/0x1e8 fs/namespace.c:446 #1: ffff0000e210e850 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000e210e850 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: chown_common+0x2b8/0x594 fs/open.c:726 #2: ffff0000e210e518 (&ei->xattr_sem){++++}-{3:3}, at: ext4_setattr+0x7c4/0x15f0 fs/ext4/inode.c:5526 #3: ffff0000f6a5c7a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x60/0x4d8 fs/quota/dquot.c:460 #4: ffff0000ce834208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 fs/quota/quota_v2.c:357 stack backtrace: CPU: 0 PID: 5880 Comm: syz.2.575 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call trace: dump_backtrace+0x1c0/0x1ec 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+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 down_read+0x64/0x300 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x278/0x1778 fs/ext4/inode.c:606 ext4_getblk+0x178/0x664 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_quota_write+0x204/0x534 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x284/0x574 fs/quota/quota_tree.c:136 do_insert_tree+0x1c4/0xc34 fs/quota/quota_tree.c:347 do_insert_tree+0x790/0xc34 fs/quota/quota_tree.c:402 do_insert_tree+0x764/0xc34 fs/quota/quota_tree.c:402 do_insert_tree+0x764/0xc34 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x3d4/0x4f0 fs/quota/quota_tree.c:451 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:361 dquot_acquire+0x2a8/0x4d8 fs/quota/dquot.c:472 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6837 dqget+0x654/0xcc4 fs/quota/dquot.c:988 dquot_transfer+0x314/0x708 fs/quota/dquot.c:2150 ext4_setattr+0x7d4/0x15f0 fs/ext4/inode.c:5527 notify_change+0xb0c/0xdcc fs/attr.c:499 chown_common+0x420/0x594 fs/open.c:736 vfs_fchown fs/open.c:804 [inline] ksys_fchown+0xe0/0x158 fs/open.c:815 __do_sys_fchown fs/open.c:823 [inline] __se_sys_fchown fs/open.c:821 [inline] __arm64_sys_fchown+0x7c/0x94 fs/open.c:821 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b4 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x130 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