EXT4-fs (loop0): mounted filesystem without journal. Quota mode: writeback. ext4 filesystem being mounted at /161/file1 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.833/6981 is trying to acquire lock: ffff888053cd2428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 but task is already holding lock: ffff888073fa3eb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x910/0x1b70 fs/ext4/inode.c:672 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+0x910/0x1b70 fs/ext4/inode.c:672 ext4_getblk+0x1cc/0x6f0 fs/ext4/inode.c:890 ext4_bread+0x26/0x170 fs/ext4/inode.c:946 ext4_quota_write+0x236/0x580 fs/ext4/super.c:7222 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x312/0x660 fs/quota/quota_tree.c:136 do_insert_tree+0x22b/0x1040 fs/quota/quota_tree.c:347 do_insert_tree+0x9eb/0x1040 fs/quota/quota_tree.c:402 do_insert_tree+0x9ae/0x1040 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x49d/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:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_file_open+0x2da/0x6f0 fs/ext4/file.c:869 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 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 -> #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:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6831 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x3c3/0xcd0 fs/quota/dquot.c:1517 ext4_file_open+0x2da/0x6f0 fs/ext4/file.c:869 do_dentry_open+0x7e9/0x10d0 fs/open.c:882 do_open fs/namei.c:3634 [inline] path_openat+0x2635/0x2ee0 fs/namei.c:3791 do_filp_open+0x1f1/0x430 fs/namei.c:3818 do_sys_openat2+0x150/0x4b0 fs/open.c:1320 do_sys_open fs/open.c:1336 [inline] __do_sys_open fs/open.c:1344 [inline] __se_sys_open fs/open.c:1340 [inline] __x64_sys_open+0x11b/0x140 fs/open.c:1340 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:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6811 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_alloc_space+0x5fc/0xe60 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+0xf8d/0x4760 fs/ext4/mballoc.c:5738 ext4_ext_map_blocks+0x195b/0x6810 fs/ext4/extents.c:4340 ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:679 ext4_iomap_alloc fs/ext4/inode.c:3438 [inline] ext4_iomap_begin+0x7fa/0xb10 fs/ext4/inode.c:3488 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 __iomap_dio_rw+0xd52/0x1e30 fs/iomap/direct-io.c:593 iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:682 ext4_dio_write_iter fs/ext4/file.c:554 [inline] ext4_file_write_iter+0x12b7/0x1710 fs/ext4/file.c:674 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x642/0xb10 fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_pwritev+0x23d/0x3a0 fs/read_write.c:1031 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.0.833/6981: #0: ffff88801d2e0460 (sb_writers#4){.+.+}-{0:0}, at: vfs_writev fs/read_write.c:933 [inline] #0: ffff88801d2e0460 (sb_writers#4){.+.+}-{0:0}, at: do_pwritev+0x226/0x3a0 fs/read_write.c:1031 #1: ffff888073fa4030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff888073fa4030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_dio_write_iter fs/ext4/file.c:492 [inline] #1: ffff888073fa4030 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_file_write_iter+0x62d/0x1710 fs/ext4/file.c:674 #2: ffff888073fa3eb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x910/0x1b70 fs/ext4/inode.c:672 #3: ffffffff8cc74988 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #3: ffffffff8cc74988 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline] #3: ffffffff8cc74988 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x173/0xe60 fs/quota/dquot.c:1716 stack backtrace: CPU: 1 PID: 6981 Comm: syz.0.833 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12d/0xaf0 kernel/locking/mutex.c:747 dquot_commit+0x5a/0x410 fs/quota/dquot.c:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6811 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:412 __dquot_alloc_space+0x5fc/0xe60 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+0xf8d/0x4760 fs/ext4/mballoc.c:5738 ext4_ext_map_blocks+0x195b/0x6810 fs/ext4/extents.c:4340 ext4_map_blocks+0x9de/0x1b70 fs/ext4/inode.c:679 ext4_iomap_alloc fs/ext4/inode.c:3438 [inline] ext4_iomap_begin+0x7fa/0xb10 fs/ext4/inode.c:3488 iomap_iter+0x6c6/0x1040 fs/iomap/iter.c:91 __iomap_dio_rw+0xd52/0x1e30 fs/iomap/direct-io.c:593 iomap_dio_rw+0x41/0xa0 fs/iomap/direct-io.c:682 ext4_dio_write_iter fs/ext4/file.c:554 [inline] ext4_file_write_iter+0x12b7/0x1710 fs/ext4/file.c:674 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x642/0xb10 fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_pwritev+0x23d/0x3a0 fs/read_write.c:1031 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: 0033:0x7efeedd9aeb9 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:00007efeeed41028 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 00007efeee015fa0 RCX: 00007efeedd9aeb9 RDX: 0000000000000014 RSI: 0000200000000240 RDI: 0000000000000004 RBP: 00007efeede08c1f R08: 0000000000000000 R09: 0000000000000003 R10: 0000000000007800 R11: 0000000000000246 R12: 0000000000000000 R13: 00007efeee016038 R14: 00007efeee015fa0 R15: 00007fff8cbf9fd8