====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.2.4003/23104 is trying to acquire lock: ffff88804918a708 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff88804918a708 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 but task is already holding lock: ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 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+0x120/0x360 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:1796 [inline] ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 __writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1719 writeback_single_inode+0x1f9/0x6a0 fs/fs-writeback.c:1840 write_inode_now+0x160/0x1d0 fs/fs-writeback.c:2903 iput_final fs/inode.c:1901 [inline] iput+0x830/0xc50 fs/inode.c:1966 ext4_xattr_block_set+0x1fce/0x2ac0 fs/ext4/xattr.c:2199 ext4_xattr_move_to_block fs/ext4/xattr.c:2664 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2739 [inline] ext4_expand_extra_isize_ea+0x12da/0x1ea0 fs/ext4/xattr.c:2827 __ext4_expand_extra_isize+0x30d/0x400 fs/ext4/inode.c:6364 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6407 [inline] __ext4_mark_inode_dirty+0x46c/0x700 fs/ext4/inode.c:6485 ext4_evict_inode+0x80d/0xee0 fs/ext4/inode.c:254 evict+0x504/0x9c0 fs/inode.c:810 ext4_orphan_cleanup+0xc20/0x1460 fs/ext4/orphan.c:470 __ext4_fill_super fs/ext4/super.c:5617 [inline] ext4_fill_super+0x5920/0x61e0 fs/ext4/super.c:5736 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691 vfs_get_tree+0x92/0x2b0 fs/super.c:1751 fc_mount fs/namespace.c:1208 [inline] do_new_mount_fc fs/namespace.c:3651 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3727 do_mount fs/namespace.c:4050 [inline] __do_sys_mount fs/namespace.c:4238 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4215 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/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 ext4_do_writepages+0x526/0x4610 fs/ext4/inode.c:2810 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_flush+0x191/0x230 mm/filemap.c:473 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); lock(&sbi->s_writepages_rwsem); lock(&ei->xattr_sem); *** DEADLOCK *** 1 lock held by syz.2.4003/23104: #0: ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #0: ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1796 [inline] #0: ffff88802e892b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1cc/0x350 fs/ext4/inode.c:3024 stack backtrace: CPU: 0 UID: 0 PID: 23104 Comm: syz.2.4003 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x28/0xe0 fs/ext4/inline.c:1787 ext4_do_writepages+0x526/0x4610 fs/ext4/inode.c:2810 ext4_writepages+0x205/0x350 fs/ext4/inode.c:3025 do_writepages+0x32e/0x550 mm/page-writeback.c:2604 filemap_fdatawrite_wbc mm/filemap.c:389 [inline] __filemap_fdatawrite_range mm/filemap.c:422 [inline] __filemap_fdatawrite mm/filemap.c:428 [inline] filemap_flush+0x191/0x230 mm/filemap.c:473 ext4_release_file+0x82/0x310 fs/ext4/file.c:169 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f019d38efc9 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:00007ffeb665d948 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f019d5e7da0 RCX: 00007f019d38efc9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f019d5e7da0 R08: 000000000001e40c R09: 0000001bb665dc3f R10: 00007f019d5e7cb0 R11: 0000000000000246 R12: 000000000016a3a4 R13: 00007f019d5e6180 R14: ffffffffffffffff R15: 00007ffeb665da60 EXT4-fs error (device loop2): ext4_mb_generate_buddy:1289: group 0, block bitmap and bg descriptor inconsistent: 25 vs 4278190105 free clusters EXT4-fs (loop2): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 32 with error 28 EXT4-fs (loop2): This should not happen!! Data will be lost EXT4-fs (loop2): Total free blocks count 0 EXT4-fs (loop2): Free/Dirty block details EXT4-fs (loop2): free_blocks=68451041280 EXT4-fs (loop2): dirty_blocks=32 EXT4-fs (loop2): Block reservation details EXT4-fs (loop2): i_reserved_data_blocks=2