====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.6497/18698 is trying to acquire lock: ffff0000f57bf3e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x1c8 fs/quota/dquot.c:535 but task is already holding lock: ffff0000f5718c90 (&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_write+0x200/0x544 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x27c/0x570 fs/quota/quota_tree.c:136 do_insert_tree+0x1ec/0xc68 fs/quota/quota_tree.c:347 do_insert_tree+0x7dc/0xc68 fs/quota/quota_tree.c:402 do_insert_tree+0x7b0/0xc68 fs/quota/quota_tree.c:402 do_insert_tree+0x7b0/0xc68 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x3d4/0x4e4 fs/quota/quota_tree.c:451 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:361 dquot_acquire+0x280/0x4b8 fs/quota/dquot.c:500 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1013 __dquot_initialize+0x280/0xb30 fs/quota/dquot.c:1542 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1604 ext4_xattr_set+0xbc/0x2b4 fs/ext4/xattr.c:2487 ext4_xattr_security_set+0x4c/0x64 fs/ext4/xattr_security.c:31 __vfs_setxattr+0x374/0x390 fs/xattr.c:182 __vfs_setxattr_noperm+0x120/0x56c fs/xattr.c:216 __vfs_setxattr_locked+0x1e8/0x214 fs/xattr.c:277 vfs_setxattr+0x158/0x2a8 fs/xattr.c:309 do_setxattr fs/xattr.c:594 [inline] setxattr+0x258/0x2d8 fs/xattr.c:617 path_setxattr+0x130/0x260 fs/xattr.c:636 __do_sys_lsetxattr fs/xattr.c:659 [inline] __se_sys_lsetxattr fs/xattr.c:655 [inline] __arm64_sys_lsetxattr+0xc4/0xe0 fs/xattr.c:655 __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:491 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1013 dquot_set_dqblk+0x40/0xe34 fs/quota/dquot.c:2858 quota_setquota+0x41c/0x4cc fs/quota/quota.c:310 do_quotactl+0x65c/0x738 fs/quota/quota.c:802 __do_sys_quotactl fs/quota/quota.c:960 [inline] __se_sys_quotactl fs/quota/quota.c:916 [inline] __arm64_sys_quotactl+0x2dc/0x77c fs/quota/quota.c:916 __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:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __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:535 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:400 [inline] mark_all_dquot_dirty+0x1f8/0x424 fs/quota/dquot.c:440 __dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1777 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_getblk+0x178/0x680 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_append+0x23c/0x488 fs/ext4/namei.c:83 ext4_add_entry+0x768/0xbbc fs/ext4/namei.c:2511 ext4_rename fs/ext4/namei.c:3976 [inline] ext4_rename2+0x15b8/0x2540 fs/ext4/namei.c:4258 vfs_rename+0xb08/0xe3c fs/namei.c:4882 do_renameat2+0x760/0xaa4 fs/namei.c:5035 __do_sys_renameat2 fs/namei.c:5068 [inline] __se_sys_renameat2 fs/namei.c:5065 [inline] __arm64_sys_renameat2+0xe8/0x104 fs/namei.c:5065 __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 *** 7 locks held by syz.0.6497/18698: #0: ffff0000c3244460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402 #1: ffff0000c3244748 (&type->s_vfs_rename_key#4){+.+.}-{3:3}, at: lock_rename fs/namei.c:3046 [inline] #1: ffff0000c3244748 (&type->s_vfs_rename_key#4){+.+.}-{3:3}, at: do_renameat2+0x314/0xaa4 fs/namei.c:4974 #2: ffff0000f5718400 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #2: ffff0000f5718400 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_two_directories fs/namei.c:-1 [inline] #2: ffff0000f5718400 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: lock_rename fs/namei.c:3047 [inline] #2: ffff0000f5718400 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: do_renameat2+0x390/0xaa4 fs/namei.c:4974 #3: ffff0000f5718e08 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: lock_rename include/linux/fs.h:-1 [inline] #3: ffff0000f5718e08 (&type->i_mutex_dir_key#3/5){+.+.}-{3:3}, at: do_renameat2+0x3c4/0xaa4 fs/namei.c:4974 #4: ffff0000f571e850 (&sb->s_type->i_mutex_key#10/4){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #4: ffff0000f571e850 (&sb->s_type->i_mutex_key#10/4){+.+.}-{3:3}, at: lock_two_nondirectories+0xb8/0x128 fs/inode.c:1210 #5: ffff0000f5718c90 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x720/0x160c fs/ext4/inode.c:674 #6: ffff80001568caa8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 18698 Comm: syz.0.6497 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 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:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 __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:535 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:400 [inline] mark_all_dquot_dirty+0x1f8/0x424 fs/quota/dquot.c:440 __dquot_alloc_space+0x564/0xcfc fs/quota/dquot.c:1777 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_getblk+0x178/0x680 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_append+0x23c/0x488 fs/ext4/namei.c:83 ext4_add_entry+0x768/0xbbc fs/ext4/namei.c:2511 ext4_rename fs/ext4/namei.c:3976 [inline] ext4_rename2+0x15b8/0x2540 fs/ext4/namei.c:4258 vfs_rename+0xb08/0xe3c fs/namei.c:4882 do_renameat2+0x760/0xaa4 fs/namei.c:5035 __do_sys_renameat2 fs/namei.c:5068 [inline] __se_sys_renameat2 fs/namei.c:5065 [inline] __arm64_sys_renameat2+0xe8/0x104 fs/namei.c:5065 __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