====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/4326 is trying to acquire lock: ffff0000f6ac55a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 but task is already holding lock: ffff0000e261aaa8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x7cc/0x1084 fs/ext4/inode.c:4290 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+0x5c/0x88 kernel/locking/rwsem.c:1573 ext4_map_blocks+0x7c4/0x1778 fs/ext4/inode.c:672 ext4_getblk+0x178/0x664 fs/ext4/inode.c:890 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:946 ext4_quota_write+0x204/0x534 fs/ext4/super.c:7222 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x548/0xa68 fs/quota/quota_tree.c:318 do_insert_tree+0x574/0xc34 fs/quota/quota_tree.c:400 do_insert_tree+0x764/0xc34 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:6831 dqget+0x654/0xcc4 fs/quota/dquot.c:988 __dquot_initialize+0x294/0xacc fs/quota/dquot.c:1517 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579 ext4_mkdir+0x150/0xa1c fs/ext4/namei.c:3059 vfs_mkdir+0x314/0x4d4 fs/namei.c:4114 do_mkdirat+0x1b8/0x3ec fs/namei.c:4139 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __arm64_sys_mkdirat+0x90/0xa8 fs/namei.c:4152 __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 (&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:6831 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:5556 [inline] ext4_fill_super+0x6188/0x660c fs/ext4/super.c:5687 get_tree_bdev+0x358/0x544 fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5717 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 -> #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+0x2880/0x6800 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x63c kernel/locking/lockdep.c:5662 __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:6811 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6888 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412 __dquot_free_space+0x73c/0xa78 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:379 [inline] dquot_free_space include/linux/quotaops.h:384 [inline] dquot_free_block include/linux/quotaops.h:395 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6154 [inline] ext4_free_blocks+0x1888/0x2390 fs/ext4/mballoc.c:6284 ext4_remove_blocks fs/ext4/extents.c:2526 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2692 [inline] ext4_ext_remove_space+0x1720/0x3a9c fs/ext4/extents.c:2940 ext4_ext_truncate+0x164/0x20c fs/ext4/extents.c:4470 ext4_truncate+0x9f4/0x1084 fs/ext4/inode.c:4295 ext4_evict_inode+0xc10/0x1278 fs/ext4/inode.c:286 evict+0x3e0/0x828 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x754/0x7e4 fs/inode.c:1860 do_unlinkat+0x36c/0x500 fs/namei.c:4405 __do_sys_unlinkat fs/namei.c:4441 [inline] __se_sys_unlinkat fs/namei.c:4434 [inline] __arm64_sys_unlinkat+0xe0/0xfc fs/namei.c:4434 __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: &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-executor/4326: #0: ffff0000fa8dc460 (sb_writers#3){++++}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402 #1: ffff0000fa8dc650 (sb_internal){++++}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline] #1: ffff0000fa8dc650 (sb_internal){++++}-{0:0}, at: sb_start_intwrite include/linux/fs.h:2013 [inline] #1: ffff0000fa8dc650 (sb_internal){++++}-{0:0}, at: ext4_evict_inode+0x3e0/0x1278 fs/ext4/inode.c:240 #2: ffff0000e261aaa8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x7cc/0x1084 fs/ext4/inode.c:4290 #3: ffff80001550c848 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 4326 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 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 __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:6811 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6888 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412 __dquot_free_space+0x73c/0xa78 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:379 [inline] dquot_free_space include/linux/quotaops.h:384 [inline] dquot_free_block include/linux/quotaops.h:395 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6154 [inline] ext4_free_blocks+0x1888/0x2390 fs/ext4/mballoc.c:6284 ext4_remove_blocks fs/ext4/extents.c:2526 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2692 [inline] ext4_ext_remove_space+0x1720/0x3a9c fs/ext4/extents.c:2940 ext4_ext_truncate+0x164/0x20c fs/ext4/extents.c:4470 ext4_truncate+0x9f4/0x1084 fs/ext4/inode.c:4295 ext4_evict_inode+0xc10/0x1278 fs/ext4/inode.c:286 evict+0x3e0/0x828 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x754/0x7e4 fs/inode.c:1860 do_unlinkat+0x36c/0x500 fs/namei.c:4405 __do_sys_unlinkat fs/namei.c:4441 [inline] __se_sys_unlinkat fs/namei.c:4434 [inline] __arm64_sys_unlinkat+0xe0/0xfc fs/namei.c:4434 __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 EXT4-fs (loop0): unmounting filesystem.