EXT4-fs (loop5): mounted filesystem without journal. Opts: errors=remount-ro,usrquota,minixdf,nombcache,. Quota mode: writeback. ext4 filesystem being mounted at /332/bus supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.5.1913/9675 is trying to acquire lock: ffff88805ec805e8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:532 but task is already holding lock: ffff8880704c3e48 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668 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_read+0x1ac/0x390 fs/ext4/super.c:6577 read_blk fs/quota/quota_tree.c:55 [inline] find_tree_dqentry+0x187/0xb30 fs/quota/quota_tree.c:617 find_tree_dqentry+0x3e8/0xb30 fs/quota/quota_tree.c:635 find_dqentry fs/quota/quota_tree.c:647 [inline] qtree_read_dquot+0x122/0x690 fs/quota/quota_tree.c:667 v2_read_dquot+0xc0/0x110 fs/quota/quota_v2.c:333 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+0x324/0xd00 fs/quota/dquot.c:1539 ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327 ext4_orphan_cleanup+0xc96/0x14f0 fs/ext4/orphan.c:472 ext4_fill_super+0x8c65/0x93f0 fs/ext4/super.c:5006 mount_bdev+0x28a/0x3c0 fs/super.c:1411 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1541 do_new_mount+0x247/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 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_set_acl+0x15e/0x5e0 fs/ext4/acl.c:237 set_posix_acl fs/posix_acl.c:947 [inline] posix_acl_xattr_set+0x324/0x390 fs/posix_acl.c:966 __vfs_setxattr+0x3d8/0x410 fs/xattr.c:182 __vfs_setxattr_noperm+0x126/0x5e0 fs/xattr.c:216 vfs_setxattr+0x167/0x2e0 fs/xattr.c:303 do_setxattr fs/xattr.c:588 [inline] setxattr+0x2cb/0x360 fs/xattr.c:611 path_setxattr+0x147/0x290 fs/xattr.c:630 __do_sys_setxattr fs/xattr.c:646 [inline] __se_sys_setxattr fs/xattr.c:642 [inline] __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:642 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:3120 [inline] check_prevs_add kernel/locking/lockdep.c:3239 [inline] validate_chain kernel/locking/lockdep.c:3855 [inline] __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120 lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737 __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_alloc_space+0x5cb/0xe10 fs/quota/dquot.c:1774 dquot_alloc_space_nodirty include/linux/quotaops.h:290 [inline] dquot_alloc_space include/linux/quotaops.h:303 [inline] dquot_alloc_block include/linux/quotaops.h:327 [inline] ext4_mb_new_blocks+0xf80/0x47c0 fs/ext4/mballoc.c:5750 ext4_ext_map_blocks+0x17d1/0x63d0 fs/ext4/extents.c:4372 ext4_map_blocks+0x97f/0x1a50 fs/ext4/inode.c:675 _ext4_get_block+0x1e7/0x540 fs/ext4/inode.c:818 ext4_block_write_begin+0x5ff/0x1200 fs/ext4/inode.c:1103 ext4_write_begin+0x6c8/0x15d0 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x442/0xb20 fs/ext4/inode.c:2977 __page_symlink+0x102/0x200 fs/namei.c:5242 ext4_symlink+0x885/0xcd0 fs/ext4/namei.c:3469 vfs_symlink+0x245/0x3d0 fs/namei.c:4480 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4509 __do_sys_symlink fs/namei.c:4531 [inline] __se_sys_symlink fs/namei.c:4529 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4529 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: &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.5.1913/9675: #0: ffff888056f60460 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x3d/0x90 fs/namespace.c:386 #1: ffff8880704d35c8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline] #1: ffff8880704d35c8 (&type->i_mutex_dir_key#4/1){+.+.}-{3:3}, at: filename_create+0x20b/0x450 fs/namei.c:3886 #2: ffff8880704c3e48 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x8c4/0x1a50 fs/ext4/inode.c:668 #3: ffffffff8d2416f8 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312 stack backtrace: CPU: 1 PID: 9675 Comm: syz.5.1913 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x2f8/0x400 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3120 [inline] check_prevs_add kernel/locking/lockdep.c:3239 [inline] validate_chain kernel/locking/lockdep.c:3855 [inline] __lock_acquire+0x38f7/0x7d40 kernel/locking/lockdep.c:5120 lock_acquire+0x19f/0x400 kernel/locking/lockdep.c:5737 __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_alloc_space+0x5cb/0xe10 fs/quota/dquot.c:1774 dquot_alloc_space_nodirty include/linux/quotaops.h:290 [inline] dquot_alloc_space include/linux/quotaops.h:303 [inline] dquot_alloc_block include/linux/quotaops.h:327 [inline] ext4_mb_new_blocks+0xf80/0x47c0 fs/ext4/mballoc.c:5750 ext4_ext_map_blocks+0x17d1/0x63d0 fs/ext4/extents.c:4372 ext4_map_blocks+0x97f/0x1a50 fs/ext4/inode.c:675 _ext4_get_block+0x1e7/0x540 fs/ext4/inode.c:818 ext4_block_write_begin+0x5ff/0x1200 fs/ext4/inode.c:1103 ext4_write_begin+0x6c8/0x15d0 fs/ext4/ext4_jbd2.h:-1 ext4_da_write_begin+0x442/0xb20 fs/ext4/inode.c:2977 __page_symlink+0x102/0x200 fs/namei.c:5242 ext4_symlink+0x885/0xcd0 fs/ext4/namei.c:3469 vfs_symlink+0x245/0x3d0 fs/namei.c:4480 do_symlinkat+0x1ab/0x6b0 fs/namei.c:4509 __do_sys_symlink fs/namei.c:4531 [inline] __se_sys_symlink fs/namei.c:4529 [inline] __x64_sys_symlink+0x7a/0x90 fs/namei.c:4529 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: 0033:0x7fd033969559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fd031bc0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058 RAX: ffffffffffffffda RBX: 00007fd033beffa0 RCX: 00007fd033969559 RDX: 0000000000000000 RSI: 0000200000001480 RDI: 0000200000001380 RBP: 00007fd033a00b20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd033bf0038 R14: 00007fd033beffa0 R15: 00007ffe6ebc4f08