EXT4-fs (loop1): mounted filesystem without journal. Quota mode: writeback. fs-verity: sha256 using implementation "sha256-ce" ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.1409/8344 is trying to acquire lock: ffff0000e259c7a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 but task is already holding lock: ffff0000f6913eb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x7c4/0x1778 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+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 fs/quota/dquot.c:1579 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2228 ext4_file_open+0x21c/0x53c fs/ext4/file.c:869 do_dentry_open+0x72c/0xf98 fs/open.c:882 vfs_open+0x7c/0x90 fs/open.c:1015 do_open fs/namei.c:3634 [inline] path_openat+0x1f8c/0x26bc fs/namei.c:3791 do_filp_open+0x194/0x384 fs/namei.c:3818 do_sys_openat2+0x134/0x3f4 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] __arm64_sys_openat+0x118/0x14c fs/open.c:1347 __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_get_dqblk+0x34/0x278 fs/quota/dquot.c:2699 quota_getquota+0x238/0x42c fs/quota/quota.c:214 do_quotactl+0x6b4/0x738 fs/quota/quota.c:798 __do_sys_quotactl fs/quota/quota.c:960 [inline] __se_sys_quotactl fs/quota/quota.c:916 [inline] __arm64_sys_quotactl+0x2cc/0x77c fs/quota/quota.c:916 __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_alloc_space+0x560/0xce0 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+0xd48/0x4338 fs/ext4/mballoc.c:5738 ext4_ext_map_blocks+0x1394/0x56f4 fs/ext4/extents.c:4340 ext4_map_blocks+0x860/0x1778 fs/ext4/inode.c:679 _ext4_get_block+0x19c/0x4d8 fs/ext4/inode.c:822 ext4_get_block_unwritten+0x3c/0x110 fs/ext4/inode.c:855 ext4_block_write_begin+0x50c/0x10e4 fs/ext4/inode.c:1124 ext4_write_begin+0x5f4/0x131c fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x348/0x990 fs/ext4/inode.c:3000 pagecache_write+0x1e0/0x394 fs/ext4/verity.c:85 ext4_write_merkle_tree_block+0xac/0xfc fs/ext4/verity.c:388 build_merkle_tree_level fs/verity/enable.c:121 [inline] build_merkle_tree fs/verity/enable.c:182 [inline] enable_verity+0xf88/0x199c fs/verity/enable.c:268 fsverity_ioctl_enable+0x3d4/0x45c fs/verity/enable.c:392 __ext4_ioctl fs/ext4/ioctl.c:1580 [inline] ext4_ioctl+0x167c/0x42dc fs/ext4/ioctl.c:1614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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 *** 3 locks held by syz.1.1409/8344: #0: ffff0000d28b0460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write_file+0x64/0x1e8 fs/namespace.c:446 #1: ffff0000f6913eb8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x7c4/0x1778 fs/ext4/inode.c:672 #2: ffff80001550c848 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 stack backtrace: CPU: 0 PID: 8344 Comm: syz.1.1409 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_alloc_space+0x560/0xce0 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+0xd48/0x4338 fs/ext4/mballoc.c:5738 ext4_ext_map_blocks+0x1394/0x56f4 fs/ext4/extents.c:4340 ext4_map_blocks+0x860/0x1778 fs/ext4/inode.c:679 _ext4_get_block+0x19c/0x4d8 fs/ext4/inode.c:822 ext4_get_block_unwritten+0x3c/0x110 fs/ext4/inode.c:855 ext4_block_write_begin+0x50c/0x10e4 fs/ext4/inode.c:1124 ext4_write_begin+0x5f4/0x131c fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x348/0x990 fs/ext4/inode.c:3000 pagecache_write+0x1e0/0x394 fs/ext4/verity.c:85 ext4_write_merkle_tree_block+0xac/0xfc fs/ext4/verity.c:388 build_merkle_tree_level fs/verity/enable.c:121 [inline] build_merkle_tree fs/verity/enable.c:182 [inline] enable_verity+0xf88/0x199c fs/verity/enable.c:268 fsverity_ioctl_enable+0x3d4/0x45c fs/verity/enable.c:392 __ext4_ioctl fs/ext4/ioctl.c:1580 [inline] ext4_ioctl+0x167c/0x42dc fs/ext4/ioctl.c:1614 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856 __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