EXT4-fs (loop2): mounted filesystem without journal. Opts: errors=remount-ro,bsddf,. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected 5.15.181-syzkaller #0 Not tainted ------------------------------------------------------ syz.2.802/7930 is trying to acquire lock: ffff0000f206e628 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 but task is already holding lock: ffff0000c21c0208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 fs/quota/quota_v2.c:354 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0xc0/0x390 kernel/locking/rwsem.c:1498 v2_read_dquot+0x4c/0x118 fs/quota/quota_v2.c:332 dquot_acquire+0x120/0x510 fs/quota/dquot.c:463 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200 dqget+0x658/0xcf4 fs/quota/dquot.c:988 __dquot_initialize+0x2d4/0xa80 fs/quota/dquot.c:1517 dquot_initialize+0x24/0x34 fs/quota/dquot.c:1579 ext4_create+0x94/0x3fc fs/ext4/namei.c:2876 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x1144/0x26e4 fs/namei.c:3739 do_filp_open+0x164/0x330 fs/namei.c:3769 do_sys_openat2+0x128/0x3d8 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x120/0x154 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #1 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common+0x194/0x1edc kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0xac/0x11c kernel/locking/mutex.c:743 dquot_commit+0x50/0x1c4 fs/quota/dquot.c:507 ext4_write_dquot+0x1b4/0x31c fs/ext4/super.c:6180 ext4_mark_dquot_dirty+0xe8/0x140 fs/ext4/super.c:6257 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:412 __dquot_free_space+0x76c/0xaa8 fs/quota/dquot.c:1942 dquot_free_space_nodirty include/linux/quotaops.h:376 [inline] dquot_free_space include/linux/quotaops.h:381 [inline] dquot_free_block include/linux/quotaops.h:392 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6156 [inline] ext4_free_blocks+0x1900/0x23cc fs/ext4/mballoc.c:6286 ext4_remove_blocks fs/ext4/extents.c:2505 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2689 [inline] ext4_ext_remove_space+0x1c98/0x3830 fs/ext4/extents.c:2937 ext4_ext_truncate+0x184/0x24c fs/ext4/extents.c:4471 ext4_truncate+0x9c0/0xf94 fs/ext4/inode.c:4250 ext4_evict_inode+0xbec/0x11dc fs/ext4/inode.c:289 evict+0x3c8/0x810 fs/inode.c:647 iput_final fs/inode.c:1769 [inline] iput+0x6c4/0x77c fs/inode.c:1795 do_unlinkat+0x360/0x600 fs/namei.c:4355 __do_sys_unlinkat fs/namei.c:4391 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __arm64_sys_unlinkat+0xe0/0xfc fs/namei.c:4384 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 -> #0 (&ei->i_data_sem/2){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 down_write+0xbc/0x12c kernel/locking/rwsem.c:1551 ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923 ext4_quota_write+0x220/0x52c fs/ext4/super.c:6591 write_blk fs/quota/quota_tree.c:64 [inline] find_free_dqentry fs/quota/quota_tree.c:307 [inline] do_insert_tree+0xd34/0x1424 fs/quota/quota_tree.c:364 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x2c4/0x3f8 fs/quota/quota_tree.c:411 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358 dquot_acquire+0x2b0/0x510 fs/quota/dquot.c:472 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200 dqget+0x658/0xcf4 fs/quota/dquot.c:988 __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517 dquot_initialize fs/quota/dquot.c:1579 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2221 ext4_file_open+0x200/0x510 fs/ext4/file.c:855 do_dentry_open+0x760/0xebc fs/open.c:826 vfs_open+0x7c/0x90 fs/open.c:956 do_open fs/namei.c:3608 [inline] path_openat+0x1f80/0x26e4 fs/namei.c:3742 do_filp_open+0x164/0x330 fs/namei.c:3769 do_sys_openat2+0x128/0x3d8 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x120/0x154 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584 other info that might help us debug this: Chain exists of: &ei->i_data_sem/2 --> &dquot->dq_lock --> &s->s_dquot.dqio_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&s->s_dquot.dqio_sem); lock(&dquot->dq_lock); lock(&s->s_dquot.dqio_sem); lock(&ei->i_data_sem/2); *** DEADLOCK *** 2 locks held by syz.2.802/7930: #0: ffff0000e8fe8428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x60/0x510 fs/quota/dquot.c:460 #1: ffff0000c21c0208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x114/0x180 fs/quota/quota_v2.c:354 stack backtrace: CPU: 0 PID: 7930 Comm: syz.2.802 Not tainted 5.15.181-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call trace: dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack+0x30/0x40 lib/dump_stack.c:88 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106 dump_stack+0x1c/0x5c lib/dump_stack.c:113 print_circular_bug+0x148/0x1b0 kernel/locking/lockdep.c:2011 check_noncircular+0x240/0x2d4 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2928/0x651c kernel/locking/lockdep.c:5012 lock_acquire+0x1f4/0x620 kernel/locking/lockdep.c:5623 down_write+0xbc/0x12c kernel/locking/rwsem.c:1551 ext4_map_blocks+0x71c/0x167c fs/ext4/inode.c:666 ext4_getblk+0x138/0x5f0 fs/ext4/inode.c:870 ext4_bread+0x3c/0x1d4 fs/ext4/inode.c:923 ext4_quota_write+0x220/0x52c fs/ext4/super.c:6591 write_blk fs/quota/quota_tree.c:64 [inline] find_free_dqentry fs/quota/quota_tree.c:307 [inline] do_insert_tree+0xd34/0x1424 fs/quota/quota_tree.c:364 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 do_insert_tree+0x450/0x1424 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x2c4/0x3f8 fs/quota/quota_tree.c:411 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:358 dquot_acquire+0x2b0/0x510 fs/quota/dquot.c:472 ext4_acquire_dquot+0x270/0x428 fs/ext4/super.c:6200 dqget+0x658/0xcf4 fs/quota/dquot.c:988 __dquot_initialize+0x264/0xa80 fs/quota/dquot.c:1517 dquot_initialize fs/quota/dquot.c:1579 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2221 ext4_file_open+0x200/0x510 fs/ext4/file.c:855 do_dentry_open+0x760/0xebc fs/open.c:826 vfs_open+0x7c/0x90 fs/open.c:956 do_open fs/namei.c:3608 [inline] path_openat+0x1f80/0x26e4 fs/namei.c:3742 do_filp_open+0x164/0x330 fs/namei.c:3769 do_sys_openat2+0x128/0x3d8 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __arm64_sys_openat+0x120/0x154 fs/open.c:1280 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584