====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.271/6844 is trying to acquire lock: ffff888076d473e8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff888076d473e8 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x2d/0xe0 fs/ext4/inline.c:1797 but task is already holding lock: ffff888079ce2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2554 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_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1813 [inline] ext4_writepages+0x21d/0x790 fs/ext4/inode.c:3018 do_writepages+0x278/0x600 mm/page-writeback.c:2554 __writeback_single_inode+0x164/0x13c0 fs/fs-writeback.c:1750 writeback_single_inode+0x4d3/0xf30 fs/fs-writeback.c:1869 write_inode_now+0x174/0x1f0 fs/fs-writeback.c:2954 iput_final fs/inode.c:1956 [inline] iput.part.0+0x7f3/0xf50 fs/inode.c:2015 iput+0x35/0x40 fs/inode.c:1981 ext4_xattr_block_set+0x6f7/0x3660 fs/ext4/xattr.c:2204 ext4_xattr_move_to_block fs/ext4/xattr.c:2669 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2744 [inline] ext4_expand_extra_isize_ea+0x17c6/0x1d70 fs/ext4/xattr.c:2832 __ext4_expand_extra_isize+0x346/0x480 fs/ext4/inode.c:6297 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6340 [inline] __ext4_mark_inode_dirty+0x693/0x8b0 fs/ext4/inode.c:6418 ext4_evict_inode+0x860/0x17c0 fs/ext4/inode.c:255 evict+0x3c2/0xad0 fs/inode.c:846 iput_final fs/inode.c:1966 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2015 iput+0x35/0x40 fs/inode.c:1981 ext4_orphan_cleanup+0x71e/0x11e0 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5670 [inline] ext4_fill_super+0x9009/0xb470 fs/ext4/super.c:5793 get_tree_bdev_flags+0x38c/0x620 fs/super.c:1694 vfs_get_tree+0x92/0x320 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3760 [inline] do_new_mount fs/namespace.c:3836 [inline] path_mount+0x7d0/0x23d0 fs/namespace.c:4146 do_mount fs/namespace.c:4159 [inline] __do_sys_mount fs/namespace.c:4348 [inline] __se_sys_mount fs/namespace.c:4325 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 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 kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x2d/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x1185/0x3f50 fs/ext4/inode.c:2804 ext4_writepages+0x347/0x790 fs/ext4/inode.c:3019 do_writepages+0x278/0x600 mm/page-writeback.c:2554 filemap_writeback+0x22d/0x2e0 mm/filemap.c:387 ext4_alloc_da_blocks+0x23e/0x2e0 fs/ext4/inode.c:3328 ext4_release_file+0x17c/0x370 fs/ext4/file.c:170 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 get_signal+0x1bd/0x21e0 kernel/signal.c:2807 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 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.4.271/6844: #0: ffff888079ce2b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: do_writepages+0x278/0x600 mm/page-writeback.c:2554 stack backtrace: CPU: 1 UID: 0 PID: 6844 Comm: syz.4.271 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_circular_bug.cold+0x178/0x1c7 kernel/locking/lockdep.c:2043 check_noncircular+0x146/0x160 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 kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x14b8/0x2630 kernel/locking/lockdep.c:5237 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1cf/0x380 kernel/locking/lockdep.c:5825 down_write+0x8b/0x1f0 kernel/locking/rwsem.c:1590 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x2d/0xe0 fs/ext4/inline.c:1797 ext4_do_writepages+0x1185/0x3f50 fs/ext4/inode.c:2804 ext4_writepages+0x347/0x790 fs/ext4/inode.c:3019 do_writepages+0x278/0x600 mm/page-writeback.c:2554 filemap_writeback+0x22d/0x2e0 mm/filemap.c:387 ext4_alloc_da_blocks+0x23e/0x2e0 fs/ext4/inode.c:3328 ext4_release_file+0x17c/0x370 fs/ext4/file.c:170 __fput+0x3ff/0xb40 fs/file_table.c:469 task_work_run+0x150/0x240 kernel/task_work.c:233 get_signal+0x1bd/0x21e0 kernel/signal.c:2807 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3fc999c629 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:00007f3fca7eb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: 0000000000080000 RBX: 00007f3fc9c16090 RCX: 00007f3fc999c629 RDX: 0000000000000000 RSI: 000000000000000b RDI: 000000000000000b RBP: 00007f3fc9a32b39 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000e3aa6ea R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3fc9c16128 R14: 00007f3fc9c16090 R15: 00007ffd7463ef08 EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 256 with error 28 EXT4-fs (loop4): This should not happen!! Data will be lost EXT4-fs (loop4): Total free blocks count 0 EXT4-fs (loop4): Free/Dirty block details EXT4-fs (loop4): free_blocks=2415919504 EXT4-fs (loop4): dirty_blocks=256 EXT4-fs (loop4): Block reservation details EXT4-fs (loop4): i_reserved_data_blocks=16