====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz-executor/4193 is trying to acquire lock: ffff88805e8df068 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:532 but task is already holding lock: ffff8880607c5c30 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x994/0x1190 fs/ext4/inode.c:4258 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+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x350/0x1a50 fs/ext4/inode.c:600 ext4_getblk+0x176/0x670 fs/ext4/inode.c:872 ext4_bread+0x26/0x180 fs/ext4/inode.c:925 ext4_quota_write+0x237/0x580 fs/ext4/super.c:6623 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x38a/0x7a0 fs/quota/quota_tree.c:125 do_insert_tree+0x21b/0x19c0 fs/quota/quota_tree.c:335 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 do_insert_tree+0x5c4/0x19c0 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x354/0x4a0 fs/quota/quota_tree.c:411 v2_write_dquot+0x108/0x190 fs/quota/quota_v2.c:358 dquot_acquire+0x2d5/0x520 fs/quota/dquot.c:497 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232 dqget+0x713/0xbb0 fs/quota/dquot.c:1010 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1539 ext4_file_open+0x2e4/0x700 fs/ext4/file.c:855 do_dentry_open+0x7f7/0xf90 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2718/0x2fb0 fs/namei.c:3750 do_filp_open+0x1df/0x400 fs/namei.c:3777 do_sys_openat2+0x14b/0x500 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_creat fs/open.c:1347 [inline] __se_sys_creat fs/open.c:1341 [inline] __x64_sys_creat+0x8c/0xb0 fs/open.c:1341 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}: down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:332 dquot_acquire+0x152/0x520 fs/quota/dquot.c:488 ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6232 dqget+0x713/0xbb0 fs/quota/dquot.c:1010 __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1539 ext4_mkdir+0x198/0xc90 fs/ext4/namei.c:3059 vfs_mkdir+0x386/0x570 fs/namei.c:4073 do_mkdirat+0x1dd/0x5c0 fs/namei.c:4098 __do_sys_mkdirat fs/namei.c:4113 [inline] __se_sys_mkdirat fs/namei.c:4111 [inline] __x64_sys_mkdirat+0x85/0x90 fs/namei.c:4111 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&dquot->dq_lock){+.+.}-{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+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 dquot_commit+0x5a/0x410 fs/quota/dquot.c:532 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:437 __dquot_free_space+0x7c3/0xb80 fs/quota/dquot.c:1964 dquot_free_space_nodirty include/linux/quotaops.h:369 [inline] dquot_free_space include/linux/quotaops.h:374 [inline] dquot_free_block include/linux/quotaops.h:385 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline] ext4_free_blocks+0x1b1b/0x24c0 fs/ext4/mballoc.c:6294 ext4_remove_blocks fs/ext4/extents.c:2522 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2706 [inline] ext4_ext_remove_space+0x22bd/0x41a0 fs/ext4/extents.c:2954 ext4_ext_truncate+0x182/0x230 fs/ext4/extents.c:4504 ext4_truncate+0xa41/0x1190 fs/ext4/inode.c:4263 ext4_evict_inode+0xb0f/0x1050 fs/ext4/inode.c:291 evict+0x4b6/0x8b0 fs/inode.c:647 __dentry_kill+0x412/0x630 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 ovl_entry_stack_free fs/overlayfs/super.c:61 [inline] ovl_dentry_release+0xa1/0x140 fs/overlayfs/super.c:74 __dentry_kill+0x47b/0x630 fs/dcache.c:591 shrink_dentry_list+0x388/0x680 fs/dcache.c:1181 shrink_dcache_parent+0xae/0x3d0 fs/dcache.c:-1 do_one_tree+0x23/0xe0 fs/dcache.c:1662 shrink_dcache_for_umount+0x65/0x110 fs/dcache.c:1679 generic_shutdown_super+0x63/0x300 fs/super.c:447 kill_anon_super+0x36/0x70 fs/super.c:1089 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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-executor/4193: #0: ffff88805e6d00e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff888079c1c650 (sb_internal){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] #1: ffff888079c1c650 (sb_internal){.+.+}-{0:0}, at: sb_start_intwrite include/linux/fs.h:1928 [inline] #1: ffff888079c1c650 (sb_internal){.+.+}-{0:0}, at: ext4_evict_inode+0x41f/0x1050 fs/ext4/inode.c:245 #2: ffff8880607c5c30 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_truncate+0x994/0x1190 fs/ext4/inode.c:4258 #3: ffffffff8c441798 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 1 PID: 4193 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 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+0x2c66/0x7b50 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 dquot_commit+0x5a/0x410 fs/quota/dquot.c:532 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6212 mark_dquot_dirty fs/quota/dquot.c:397 [inline] mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:437 __dquot_free_space+0x7c3/0xb80 fs/quota/dquot.c:1964 dquot_free_space_nodirty include/linux/quotaops.h:369 [inline] dquot_free_space include/linux/quotaops.h:374 [inline] dquot_free_block include/linux/quotaops.h:385 [inline] ext4_mb_clear_bb fs/ext4/mballoc.c:6164 [inline] ext4_free_blocks+0x1b1b/0x24c0 fs/ext4/mballoc.c:6294 ext4_remove_blocks fs/ext4/extents.c:2522 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2706 [inline] ext4_ext_remove_space+0x22bd/0x41a0 fs/ext4/extents.c:2954 ext4_ext_truncate+0x182/0x230 fs/ext4/extents.c:4504 ext4_truncate+0xa41/0x1190 fs/ext4/inode.c:4263 ext4_evict_inode+0xb0f/0x1050 fs/ext4/inode.c:291 evict+0x4b6/0x8b0 fs/inode.c:647 __dentry_kill+0x412/0x630 fs/dcache.c:586 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xd8/0x1a0 fs/dcache.c:893 ovl_entry_stack_free fs/overlayfs/super.c:61 [inline] ovl_dentry_release+0xa1/0x140 fs/overlayfs/super.c:74 __dentry_kill+0x47b/0x630 fs/dcache.c:591 shrink_dentry_list+0x388/0x680 fs/dcache.c:1181 shrink_dcache_parent+0xae/0x3d0 fs/dcache.c:-1 do_one_tree+0x23/0xe0 fs/dcache.c:1662 shrink_dcache_for_umount+0x65/0x110 fs/dcache.c:1679 generic_shutdown_super+0x63/0x300 fs/super.c:447 kill_anon_super+0x36/0x70 fs/super.c:1089 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f95ba27e0d7 Code: a2 c7 05 1c 26 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffdcaffb9c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f95ba27e0d7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdcaffba80 RBP: 00007ffdcaffba80 R08: 00007ffdcaffca80 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdcaffcb70 R13: 00007f95ba31230a R14: 0000000000015691 R15: 00007ffdcaffdc40 ntfs3: loop0: ntfs_evict_inode r=5 failed, -22.