EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback. ext4 filesystem being mounted at /117/file2 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.592/5842 is trying to acquire lock: ffff888055b260a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:535 but task is already holding lock: ffff88807201aaa8 (&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_mkdir+0x198/0xc90 fs/ext4/namei.c:3059 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 -> #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_initialize+0x3a9/0xd00 fs/quota/dquot.c:1542 ext4_file_open+0x2da/0x6f0 fs/ext4/file.c:869 do_dentry_open+0x7dd/0x10b0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2674/0x2f10 fs/namei.c:3791 do_filp_open+0x1ee/0x420 fs/namei.c:3818 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1347 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_get_block+0x1e7/0x540 fs/ext4/inode.c:824 ext4_block_write_begin+0x63b/0x12f0 fs/ext4/inode.c:1126 ext4_write_begin+0x623/0xf40 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x408/0x920 fs/ext4/inode.c:3002 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862 ext4_buffered_write_iter+0x112/0x380 fs/ext4/file.c:285 ext4_file_write_iter+0x1e3/0x17d0 fs/ext4/file.c:-1 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x638/0xb10 fs/read_write.c:861 iter_file_splice_write+0x6be/0xcf0 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0xe1/0x130 fs/splice.c:950 splice_direct_to_actor+0x4b8/0xbd0 fs/splice.c:896 do_splice_direct+0x1ce/0x2f0 fs/splice.c:1002 do_sendfile+0x51b/0xe20 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1309 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.0.592/5842: #0: ffff888079dd4460 (sb_writers#4){.+.+}-{0:0}, at: do_sendfile+0x4f6/0xe20 fs/read_write.c:1254 #1: ffff88807201ac20 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff88807201ac20 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_buffered_write_iter+0xa1/0x380 fs/ext4/file.c:279 #2: ffff88807201aaa8 (&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: 0 PID: 5842 Comm: syz.0.592 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_get_block+0x1e7/0x540 fs/ext4/inode.c:824 ext4_block_write_begin+0x63b/0x12f0 fs/ext4/inode.c:1126 ext4_write_begin+0x623/0xf40 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x408/0x920 fs/ext4/inode.c:3002 generic_perform_write+0x2fa/0x5c0 mm/filemap.c:3862 ext4_buffered_write_iter+0x112/0x380 fs/ext4/file.c:285 ext4_file_write_iter+0x1e3/0x17d0 fs/ext4/file.c:-1 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x638/0xb10 fs/read_write.c:861 iter_file_splice_write+0x6be/0xcf0 fs/splice.c:685 do_splice_from fs/splice.c:763 [inline] direct_splice_actor+0xe1/0x130 fs/splice.c:950 splice_direct_to_actor+0x4b8/0xbd0 fs/splice.c:896 do_splice_direct+0x1ce/0x2f0 fs/splice.c:1002 do_sendfile+0x51b/0xe20 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1309 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: 0033:0x7f073779e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 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:00007f07385f1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f0737a25fa0 RCX: 00007f073779e0d9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004 RBP: 00007f0737835024 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000e3aa6ea R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0737a26038 R14: 00007f0737a25fa0 R15: 00007ffeb2f59c48 EXT4-fs error (device loop0): ext4_mb_mark_diskspace_used:3861: comm syz.0.592: Allocating blocks 64-65 which overlap fs metadata EXT4-fs error (device loop0): ext4_mb_mark_diskspace_used:3861: comm syz.0.592: Allocating blocks 64-65 which overlap fs metadata