EXT4-fs (loop6): mounted filesystem without journal. Quota mode: writeback. ext4 filesystem being mounted at /882/file1 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.6.6961/20190 is trying to acquire lock: ffff888055605068 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:535 but task is already holding lock: ffff8880555fa0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 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_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_quota_write+0x237/0x580 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] find_free_dqentry+0x68c/0xc30 fs/quota/quota_tree.c:318 do_insert_tree+0x717/0x1060 fs/quota/quota_tree.c:400 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 do_insert_tree+0x9b8/0x1060 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49b/0x5d0 fs/quota/quota_tree.c:451 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:361 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:500 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6837 dqget+0x713/0xbb0 fs/quota/dquot.c:1013 __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1542 ext4_unlink+0x143/0x600 fs/ext4/namei.c:3363 vfs_unlink+0x376/0x600 fs/namei.c:4330 do_unlinkat+0x335/0x580 fs/namei.c:4398 __do_sys_unlinkat fs/namei.c:4441 [inline] __se_sys_unlinkat fs/namei.c:4434 [inline] __x64_sys_unlinkat+0xd1/0xe0 fs/namei.c:4434 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335 dquot_acquire+0x152/0x520 fs/quota/dquot.c:491 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6837 dqget+0x713/0xbb0 fs/quota/dquot.c:1013 dquot_set_dqblk+0x27/0xfb0 fs/quota/dquot.c:2858 quota_setquota+0x4d6/0x590 fs/quota/quota.c:310 __do_sys_quotactl fs/quota/quota.c:960 [inline] __se_sys_quotactl+0x28b/0x6f0 fs/quota/quota.c:916 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #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+0x2d18/0x7c40 kernel/locking/lockdep.c:5063 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:535 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817 mark_dquot_dirty fs/quota/dquot.c:400 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440 __dquot_alloc_space+0x5f6/0xe50 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+0xf55/0x44d0 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x18d1/0x6640 fs/ext4/extents.c:4361 ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_append+0x2bb/0x560 fs/ext4/namei.c:83 ext4_init_new_dir+0x2b8/0x550 fs/ext4/namei.c:3030 ext4_mkdir+0x4c3/0xc90 fs/ext4/namei.c:3076 vfs_mkdir+0x386/0x570 fs/namei.c:4114 do_mkdirat+0x1d8/0x440 fs/namei.c:4139 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 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.6.6961/20190: #0: ffff888058eca460 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:402 #1: ffff88806fcd2218 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:793 [inline] #1: ffff88806fcd2218 (&type->i_mutex_dir_key#3/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3884 #2: ffff8880555fa0a0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674 #3: ffffffff8cc750a8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8cc750a8 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #3: ffffffff8cc750a8 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x16e/0xe50 fs/quota/dquot.c:1741 stack backtrace: CPU: 1 PID: 20190 Comm: syz.6.6961 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2d18/0x7c40 kernel/locking/lockdep.c:5063 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:535 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817 mark_dquot_dirty fs/quota/dquot.c:400 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440 __dquot_alloc_space+0x5f6/0xe50 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+0xf55/0x44d0 fs/ext4/mballoc.c:5740 ext4_ext_map_blocks+0x18d1/0x6640 fs/ext4/extents.c:4361 ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681 ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892 ext4_bread+0x26/0x170 fs/ext4/inode.c:948 ext4_append+0x2bb/0x560 fs/ext4/namei.c:83 ext4_init_new_dir+0x2b8/0x550 fs/ext4/namei.c:3030 ext4_mkdir+0x4c3/0xc90 fs/ext4/namei.c:3076 vfs_mkdir+0x386/0x570 fs/namei.c:4114 do_mkdirat+0x1d8/0x440 fs/namei.c:4139 __do_sys_mkdirat fs/namei.c:4154 [inline] __se_sys_mkdirat fs/namei.c:4152 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4152 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb2f1b9ce87 Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb2f2b02e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fb2f2b02ee0 RCX: 00007fb2f1b9ce87 RDX: 00000000000001ff RSI: 0000200000000800 RDI: 00000000ffffff9c RBP: 0000200000000080 R08: 0000200000000280 R09: 0000000000000000 R10: 0000200000000080 R11: 0000000000000246 R12: 0000200000000800 R13: 00007fb2f2b02ea0 R14: 0000000000000000 R15: 0000000000000000