====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.247/5877 is trying to acquire lock: ffff0000f516db10 (&ei->xattr_sem){++++}-{3:3}, at: ext4_xattr_get+0xec/0x544 fs/ext4/xattr.c:660 but task is already holding lock: ffff0000df42ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x204/0xbfc fs/ext4/migrate.c:437 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_read+0x70/0x2a8 include/linux/percpu-rwsem.h:51 ext4_writepages+0x188/0x284c fs/ext4/inode.c:2715 do_writepages+0x2c0/0x4fc mm/page-writeback.c:2491 __writeback_single_inode+0x164/0x157c fs/fs-writeback.c:1622 writeback_single_inode+0x1c0/0x720 fs/fs-writeback.c:1743 write_inode_now+0x144/0x1b0 fs/fs-writeback.c:2780 iput_final fs/inode.c:1821 [inline] iput+0x5cc/0x7f4 fs/inode.c:1860 ext4_xattr_block_set+0x17a4/0x2810 fs/ext4/xattr.c:2158 ext4_xattr_move_to_block fs/ext4/xattr.c:2626 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2701 [inline] ext4_expand_extra_isize_ea+0xcb8/0x15cc fs/ext4/xattr.c:2793 __ext4_expand_extra_isize+0x298/0x358 fs/ext4/inode.c:5980 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6023 [inline] __ext4_mark_inode_dirty+0x3e4/0x790 fs/ext4/inode.c:6101 ext4_evict_inode+0xb58/0x1270 fs/ext4/inode.c:279 evict+0x3c8/0x810 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x764/0x7f4 fs/inode.c:1860 ext4_process_orphan+0x240/0x2b4 fs/ext4/orphan.c:356 ext4_orphan_cleanup+0x908/0x104c fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5530 [inline] ext4_fill_super+0x6440/0x68a8 fs/ext4/super.c:5661 get_tree_bdev+0x358/0x544 fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5691 vfs_get_tree+0x90/0x274 fs/super.c:1573 do_new_mount+0x228/0x810 fs/namespace.c:3078 path_mount+0x5b4/0xe78 fs/namespace.c:3408 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount fs/namespace.c:3606 [inline] __arm64_sys_mount+0x49c/0x584 fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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 (&ei->xattr_sem){++++}-{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+0x293c/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 down_read+0x64/0x304 kernel/locking/rwsem.c:1520 ext4_xattr_get+0xec/0x544 fs/ext4/xattr.c:660 ext4_get_acl+0x94/0x5f0 fs/ext4/acl.c:165 get_acl+0x160/0x33c fs/posix_acl.c:153 posix_acl_create+0x104/0x3d0 fs/posix_acl.c:632 ext4_init_acl+0xac/0x340 fs/ext4/acl.c:283 __ext4_new_inode+0x27b8/0x3340 fs/ext4/ialloc.c:1328 ext4_ext_migrate+0x498/0xbfc fs/ext4/migrate.c:455 ext4_ioctl_setflags fs/ext4/ioctl.c:695 [inline] ext4_fileattr_set+0xc30/0x12c0 fs/ext4/ioctl.c:1008 vfs_fileattr_set+0x674/0x8fc fs/ioctl.c:696 do_vfs_ioctl+0x1a58/0x206c fs/ioctl.c:-1 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by syz.4.247/5877: #0: ffff0000df428460 (sb_writers#3){.+.+}-{0:0}, at: mnt_want_write_file+0x64/0x1e8 fs/namespace.c:446 #1: ffff0000f516de48 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline] #1: ffff0000f516de48 (&type->i_mutex_dir_key#3){++++}-{3:3}, at: vfs_fileattr_set+0x108/0x8fc fs/ioctl.c:681 #2: ffff0000df42ab98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x204/0xbfc fs/ext4/migrate.c:437 stack backtrace: CPU: 1 PID: 5877 Comm: syz.4.247 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 Call trace: dump_backtrace+0x1c8/0x1f4 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+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:2048 check_noncircular+0x240/0x2d4 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+0x293c/0x6544 kernel/locking/lockdep.c:5049 lock_acquire+0x20c/0x644 kernel/locking/lockdep.c:5662 down_read+0x64/0x304 kernel/locking/rwsem.c:1520 ext4_xattr_get+0xec/0x544 fs/ext4/xattr.c:660 ext4_get_acl+0x94/0x5f0 fs/ext4/acl.c:165 get_acl+0x160/0x33c fs/posix_acl.c:153 posix_acl_create+0x104/0x3d0 fs/posix_acl.c:632 ext4_init_acl+0xac/0x340 fs/ext4/acl.c:283 __ext4_new_inode+0x27b8/0x3340 fs/ext4/ialloc.c:1328 ext4_ext_migrate+0x498/0xbfc fs/ext4/migrate.c:455 ext4_ioctl_setflags fs/ext4/ioctl.c:695 [inline] ext4_fileattr_set+0xc30/0x12c0 fs/ext4/ioctl.c:1008 vfs_fileattr_set+0x674/0x8fc fs/ioctl.c:696 do_vfs_ioctl+0x1a58/0x206c fs/ioctl.c:-1 __do_sys_ioctl fs/ioctl.c:868 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __arm64_sys_ioctl+0xe4/0x1c8 fs/ioctl.c:856 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x138 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