====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.2573/16491 is trying to acquire lock: ffff888067da1da8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 but task is already holding lock: ffff8880532c8b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1811 [inline] ffff8880532c8b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f3/0x1010 fs/ext4/migrate.c:438 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 percpu_down_read_internal+0x48/0x1c0 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1799 [inline] ext4_writepages+0x1ca/0x350 fs/ext4/inode.c:3028 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 __writeback_single_inode+0x133/0x12f0 fs/fs-writeback.c:1737 writeback_single_inode+0x493/0xc70 fs/fs-writeback.c:1858 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2924 iput_final fs/inode.c:1948 [inline] iput+0xa9b/0x1050 fs/inode.c:2010 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2203 ext4_xattr_move_to_block fs/ext4/xattr.c:2668 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2743 [inline] ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2831 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6367 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6410 [inline] __ext4_mark_inode_dirty+0x45c/0x700 fs/ext4/inode.c:6488 ext4_evict_inode+0x79c/0xe80 fs/ext4/inode.c:253 evict+0x5f4/0xae0 fs/inode.c:837 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5620 [inline] ext4_fill_super+0x5946/0x6200 fs/ext4/super.c:5739 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1209 [inline] do_new_mount_fc fs/namespace.c:3658 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3734 do_mount fs/namespace.c:4057 [inline] __do_sys_mount fs/namespace.c:4246 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4223 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ei->xattr_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2130 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 ext4_get_acl+0x84/0x930 fs/ext4/acl.c:165 __get_acl+0x279/0x400 fs/posix_acl.c:159 get_inode_acl fs/posix_acl.c:184 [inline] posix_acl_create+0x134/0x4a0 fs/posix_acl.c:646 ext4_init_acl+0xb3/0x320 fs/ext4/acl.c:284 __ext4_new_inode+0x31fc/0x3cb0 fs/ext4/ialloc.c:1320 ext4_ext_migrate+0x69f/0x1010 fs/ext4/migrate.c:456 ext4_ioctl_setflags fs/ext4/ioctl.c:705 [inline] ext4_fileattr_set+0xeaf/0x1630 fs/ext4/ioctl.c:1024 vfs_fileattr_set+0x932/0xb90 fs/file_attr.c:298 ioctl_setflags+0x180/0x1e0 fs/file_attr.c:333 do_vfs_ioctl+0x8ed/0x1430 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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); rlock(&ei->xattr_sem); *** DEADLOCK *** 3 locks held by syz.2.2573/16491: #0: ffff88807cad4420 (sb_writers#4){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:553 #1: ffff888067da20c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline] #1: ffff888067da20c0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: vfs_fileattr_set+0x14e/0xb90 fs/file_attr.c:278 #2: ffff8880532c8b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_write fs/ext4/ext4.h:1811 [inline] #2: ffff8880532c8b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_ext_migrate+0x2f3/0x1010 fs/ext4/migrate.c:438 stack backtrace: CPU: 1 UID: 0 PID: 16491 Comm: syz.2.2573 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2130 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x350 kernel/locking/lockdep.c:5868 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537 ext4_xattr_get+0x10a/0x6a0 fs/ext4/xattr.c:708 ext4_get_acl+0x84/0x930 fs/ext4/acl.c:165 __get_acl+0x279/0x400 fs/posix_acl.c:159 get_inode_acl fs/posix_acl.c:184 [inline] posix_acl_create+0x134/0x4a0 fs/posix_acl.c:646 ext4_init_acl+0xb3/0x320 fs/ext4/acl.c:284 __ext4_new_inode+0x31fc/0x3cb0 fs/ext4/ialloc.c:1320 ext4_ext_migrate+0x69f/0x1010 fs/ext4/migrate.c:456 ext4_ioctl_setflags fs/ext4/ioctl.c:705 [inline] ext4_fileattr_set+0xeaf/0x1630 fs/ext4/ioctl.c:1024 vfs_fileattr_set+0x932/0xb90 fs/file_attr.c:298 ioctl_setflags+0x180/0x1e0 fs/file_attr.c:333 do_vfs_ioctl+0x8ed/0x1430 fs/ioctl.c:560 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0301f8f749 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:00007f0302e1d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f03021e6090 RCX: 00007f0301f8f749 RDX: 0000200000000080 RSI: 0000000040086602 RDI: 0000000000000006 RBP: 00007f0302013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f03021e6128 R14: 00007f03021e6090 R15: 00007fff2e846c88