====================================================== WARNING: possible circular locking dependency detected 5.15.180-syzkaller #0 Not tainted ------------------------------------------------------ syz.5.118/4876 is trying to acquire lock: ffff8880615abe48 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x332/0x1c60 fs/ext4/inode.c:597 but task is already holding lock: ffff88801a59c208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 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+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:463 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6200 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x328/0xcb0 fs/quota/dquot.c:1517 ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:329 ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:474 ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3540 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 (&dquot->dq_lock){+.+.}-{3:3}: __mutex_lock_common+0x1eb/0x2390 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:507 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6180 mark_dquot_dirty fs/quota/dquot.c:372 [inline] mark_all_dquot_dirty+0x1e3/0x400 fs/quota/dquot.c:412 __dquot_free_space+0x7ca/0xb90 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+0x1af5/0x2480 fs/ext4/mballoc.c:6286 ext4_remove_blocks fs/ext4/extents.c:2523 [inline] ext4_ext_rm_leaf fs/ext4/extents.c:2689 [inline] ext4_ext_remove_space+0x1eaa/0x4390 fs/ext4/extents.c:2937 ext4_ext_truncate+0x192/0x240 fs/ext4/extents.c:4471 ext4_truncate+0x9f1/0x10d0 fs/ext4/inode.c:4249 ext4_evict_inode+0xb43/0x1080 fs/ext4/inode.c:289 evict+0x485/0x870 fs/inode.c:647 ext4_orphan_cleanup+0xaa9/0x12e0 fs/ext4/orphan.c:474 ext4_fill_super+0x9288/0x9a00 fs/ext4/super.c:4975 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3012 do_mount fs/namespace.c:3355 [inline] __do_sys_mount fs/namespace.c:3563 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3540 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 (&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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x332/0x1c60 fs/ext4/inode.c:597 ext4_getblk+0x16d/0x630 fs/ext4/inode.c:869 ext4_bread+0x26/0x180 fs/ext4/inode.c:922 ext4_quota_write+0x230/0x570 fs/ext4/super.c:6574 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125 find_free_dqentry fs/quota/quota_tree.c:271 [inline] do_insert_tree+0xc9a/0x1970 fs/quota/quota_tree.c:364 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x361/0x4b0 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:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6200 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x328/0xcb0 fs/quota/dquot.c:1517 ext4_create+0x8c/0x460 fs/ext4/namei.c:2876 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x11e1/0x2f30 fs/namei.c:3739 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 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] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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 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 *** 4 locks held by syz.5.118/4876: #0: ffff88801a59c460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:377 #1: ffff8880615ac9b8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #1: ffff8880615ac9b8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: open_last_lookups fs/namei.c:3529 [inline] #1: ffff8880615ac9b8 (&type->i_mutex_dir_key#4){++++}-{3:3}, at: path_openat+0x7f3/0x2f30 fs/namei.c:3739 #2: ffff88805ecae428 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_acquire+0x63/0x520 fs/quota/dquot.c:460 #3: ffff88801a59c208 (&s->s_dquot.dqio_sem){++++}-{3:3}, at: v2_write_dquot+0x12b/0x190 fs/quota/quota_v2.c:354 stack backtrace: CPU: 1 PID: 4876 Comm: syz.5.118 Not tainted 5.15.180-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 ext4_map_blocks+0x332/0x1c60 fs/ext4/inode.c:597 ext4_getblk+0x16d/0x630 fs/ext4/inode.c:869 ext4_bread+0x26/0x180 fs/ext4/inode.c:922 ext4_quota_write+0x230/0x570 fs/ext4/super.c:6574 write_blk fs/quota/quota_tree.c:64 [inline] get_free_dqblk+0x387/0x7d0 fs/quota/quota_tree.c:125 find_free_dqentry fs/quota/quota_tree.c:271 [inline] do_insert_tree+0xc9a/0x1970 fs/quota/quota_tree.c:364 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 do_insert_tree+0x5b1/0x1970 fs/quota/quota_tree.c:366 dq_insert_tree fs/quota/quota_tree.c:392 [inline] qtree_write_dquot+0x361/0x4b0 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:472 ext4_acquire_dquot+0x2d9/0x4a0 fs/ext4/super.c:6200 dqget+0x778/0xeb0 fs/quota/dquot.c:988 __dquot_initialize+0x328/0xcb0 fs/quota/dquot.c:1517 ext4_create+0x8c/0x460 fs/ext4/namei.c:2876 lookup_open fs/namei.c:3462 [inline] open_last_lookups fs/namei.c:3532 [inline] path_openat+0x11e1/0x2f30 fs/namei.c:3739 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769 do_sys_openat2+0x142/0x4a0 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] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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 RIP: 0033:0x7f8d819cc969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8d7f7f2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f8d81bf4160 RCX: 00007f8d819cc969 RDX: 000000000000275a RSI: 0000200000000080 RDI: ffffffffffffff9c RBP: 00007f8d81a4eab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f8d81bf4160 R15: 00007ffcbc85ac08