loop8: detected capacity change from 0 to 4096 EXT4-fs (loop8): mounted filesystem without journal. Quota mode: writeback. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.8.814/7255 is trying to acquire lock: ffff0000e23c47a8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x54/0x1c8 fs/quota/dquot.c:532 but task is already holding lock: ffff0000f59fb4b0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x7d8/0x1090 fs/ext4/inode.c:4297 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_read+0x64/0x300 kernel/locking/rwsem.c:1520 ext4_map_blocks+0x270/0x160c fs/ext4/inode.c:606 ext4_getblk+0x178/0x680 fs/ext4/inode.c:892 ext4_bread+0x3c/0x1a8 fs/ext4/inode.c:948 ext4_quota_write+0x200/0x544 fs/ext4/super.c:7228 write_blk fs/quota/quota_tree.c:70 [inline] get_free_dqblk+0x27c/0x570 fs/quota/quota_tree.c:136 do_insert_tree+0x1ec/0xc68 fs/quota/quota_tree.c:347 do_insert_tree+0x7dc/0xc68 fs/quota/quota_tree.c:402 do_insert_tree+0x7dc/0xc68 fs/quota/quota_tree.c:402 do_insert_tree+0x7dc/0xc68 fs/quota/quota_tree.c:402 dq_insert_tree fs/quota/quota_tree.c:432 [inline] qtree_write_dquot+0x3d4/0x4e4 fs/quota/quota_tree.c:451 v2_write_dquot+0xf0/0x180 fs/quota/quota_v2.c:361 dquot_acquire+0x280/0x4b8 fs/quota/dquot.c:497 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1010 __dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1539 dquot_initialize fs/quota/dquot.c:1601 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2250 ext4_file_open+0x21c/0x540 fs/ext4/file.c:869 do_dentry_open+0x738/0xf8c fs/open.c:882 vfs_open+0x7c/0x90 fs/open.c:1015 do_open fs/namei.c:3634 [inline] path_openat+0x1fc0/0x27a0 fs/namei.c:3791 do_filp_open+0x198/0x38c fs/namei.c:3818 do_sys_openat2+0x134/0x3fc 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+0x11c/0x150 fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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+0x108/0x4b8 fs/quota/dquot.c:488 ext4_acquire_dquot+0x270/0x420 fs/ext4/super.c:6837 dqget+0x638/0xa98 fs/quota/dquot.c:1010 __dquot_initialize+0x2e4/0xb30 fs/quota/dquot.c:1539 dquot_initialize fs/quota/dquot.c:1601 [inline] dquot_file_open+0x90/0xc8 fs/quota/dquot.c:2250 ext4_file_open+0x21c/0x540 fs/ext4/file.c:869 do_dentry_open+0x738/0xf8c fs/open.c:882 vfs_open+0x7c/0x90 fs/open.c:1015 do_open fs/namei.c:3634 [inline] path_openat+0x1fc0/0x27a0 fs/namei.c:3791 do_filp_open+0x198/0x38c fs/namei.c:3818 do_sys_openat2+0x134/0x3fc 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+0x11c/0x150 fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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+0x27c8/0x6610 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x1a0/0x1f3c 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+0x54/0x1c8 fs/quota/dquot.c:532 ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817 ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:437 __dquot_free_space+0x768/0xaa4 fs/quota/dquot.c:1964 dquot_free_space_nodirty include/linux/quotaops.h:372 [inline] dquot_free_space include/linux/quotaops.h:377 [inline] dquot_free_block include/linux/quotaops.h:388 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6153 [inline] ext4_free_blocks+0x18dc/0x2468 fs/ext4/mballoc.c:6283 ext4_remove_blocks fs/ext4/extents.c:2523 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2707 [inline] ext4_ext_remove_space+0x1978/0x3b98 fs/ext4/extents.c:2955 ext4_ext_truncate+0x170/0x218 fs/ext4/extents.c:4491 ext4_truncate+0xa00/0x1090 fs/ext4/inode.c:4302 ext4_setattr+0xe34/0x15e4 fs/ext4/inode.c:5668 notify_change+0xb5c/0xe20 fs/attr.c:499 do_truncate+0x188/0x20c fs/open.c:65 handle_truncate fs/namei.c:3293 [inline] do_open fs/namei.c:3638 [inline] path_openat+0x21c8/0x27a0 fs/namei.c:3791 do_filp_open+0x198/0x38c fs/namei.c:3818 do_sys_openat2+0x134/0x3fc 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+0x11c/0x150 fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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 *** 5 locks held by syz.8.814/7255: #0: ffff0000d5fe0460 (sb_writers#3){++++}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:402 #1: ffff0000f59fb628 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000f59fb628 (&sb->s_type->i_mutex_key#10){++++}-{3:3}, at: do_truncate+0x174/0x20c fs/open.c:63 #2: ffff0000f59fb7c8 (mapping.invalidate_lock#2){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:803 [inline] #2: ffff0000f59fb7c8 (mapping.invalidate_lock#2){++++}-{3:3}, at: ext4_setattr+0xc5c/0x15e4 fs/ext4/inode.c:5591 #3: ffff0000f59fb4b0 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x7d8/0x1090 fs/ext4/inode.c:4297 #4: ffff80001563c968 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:349 stack backtrace: CPU: 1 PID: 7255 Comm: syz.8.814 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 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+0x27c8/0x6610 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5662 __mutex_lock_common+0x1a0/0x1f3c 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+0x54/0x1c8 fs/quota/dquot.c:532 ext4_write_dquot+0x1b4/0x320 fs/ext4/super.c:6817 ext4_mark_dquot_dirty+0xe8/0x150 fs/ext4/super.c:6894 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0x108/0x424 fs/quota/dquot.c:437 __dquot_free_space+0x768/0xaa4 fs/quota/dquot.c:1964 dquot_free_space_nodirty include/linux/quotaops.h:372 [inline] dquot_free_space include/linux/quotaops.h:377 [inline] dquot_free_block include/linux/quotaops.h:388 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6153 [inline] ext4_free_blocks+0x18dc/0x2468 fs/ext4/mballoc.c:6283 ext4_remove_blocks fs/ext4/extents.c:2523 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2707 [inline] ext4_ext_remove_space+0x1978/0x3b98 fs/ext4/extents.c:2955 ext4_ext_truncate+0x170/0x218 fs/ext4/extents.c:4491 ext4_truncate+0xa00/0x1090 fs/ext4/inode.c:4302 ext4_setattr+0xe34/0x15e4 fs/ext4/inode.c:5668 notify_change+0xb5c/0xe20 fs/attr.c:499 do_truncate+0x188/0x20c fs/open.c:65 handle_truncate fs/namei.c:3293 [inline] do_open fs/namei.c:3638 [inline] path_openat+0x21c8/0x27a0 fs/namei.c:3791 do_filp_open+0x198/0x38c fs/namei.c:3818 do_sys_openat2+0x134/0x3fc 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+0x11c/0x150 fs/open.c:1347 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 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 EXT4-fs error (device loop8): ext4_do_update_inode:5279: inode #15: comm syz.8.814: corrupted inode contents EXT4-fs error (device loop8): ext4_dirty_inode:6156: inode #15: comm syz.8.814: mark_inode_dirty error EXT4-fs error (device loop8): ext4_do_update_inode:5279: inode #15: comm syz.8.814: corrupted inode contents EXT4-fs error (device loop8): __ext4_ext_dirty:202: inode #15: comm syz.8.814: mark_inode_dirty error EXT4-fs error (device loop8): ext4_do_update_inode:5279: inode #15: comm syz.8.814: corrupted inode contents EXT4-fs error (device loop8): __ext4_ext_dirty:202: inode #15: comm syz.8.814: mark_inode_dirty error EXT4-fs error (device loop8): ext4_do_update_inode:5279: inode #15: comm syz.8.814: corrupted inode contents EXT4-fs error (device loop8): ext4_truncate:4325: inode #15: comm syz.8.814: mark_inode_dirty error EXT4-fs error (device loop8) in ext4_setattr:5695: Corrupt filesystem EXT4-fs (loop8): unmounting filesystem.