EXT4-fs (loop0): mounted filesystem without journal. Quota mode: none. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.392/5822 is trying to acquire lock: ffff0000e1b11ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff0000e1b11ee0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1930 but task is already holding lock: ffff0000de32cc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1b0/0x28fc fs/ext4/inode.c:2717 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+0x1b0/0x28fc fs/ext4/inode.c:2717 do_writepages+0x2c4/0x50c mm/page-writeback.c:2491 __writeback_single_inode+0x164/0x157c fs/fs-writeback.c:1673 writeback_single_inode+0x1cc/0x73c fs/fs-writeback.c:1794 write_inode_now+0x150/0x1cc fs/fs-writeback.c:2837 iput_final fs/inode.c:1821 [inline] iput+0x5b8/0x7e8 fs/inode.c:1860 ext4_xattr_block_set+0x1474/0x28b4 fs/ext4/xattr.c:2148 ext4_xattr_move_to_block fs/ext4/xattr.c:2613 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2688 [inline] ext4_expand_extra_isize_ea+0xea4/0x1818 fs/ext4/xattr.c:2776 __ext4_expand_extra_isize+0x2a0/0x364 fs/ext4/inode.c:6003 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6046 [inline] __ext4_mark_inode_dirty+0x3d4/0x7b4 fs/ext4/inode.c:6124 ext4_evict_inode+0xb50/0x1264 fs/ext4/inode.c:281 evict+0x3d8/0x824 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x728/0x7e8 fs/inode.c:1860 ext4_process_orphan+0x24c/0x2c0 fs/ext4/orphan.c:358 ext4_orphan_cleanup+0x964/0x1090 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x5af8/0x63bc fs/ext4/super.c:5693 get_tree_bdev+0x35c/0x54c fs/super.c:1366 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5723 vfs_get_tree+0x90/0x278 fs/super.c:1573 do_new_mount+0x228/0x804 fs/namespace.c:3078 path_mount+0x5ac/0xe6c 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+0x4a0/0x5a0 fs/namespace.c:3606 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140 do_el0_svc+0x5c/0x134 arch/arm64/kernel/syscall.c:204 el0_svc+0x58/0x128 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:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 down_write+0x5c/0x88 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1930 ext4_writepages+0x42c/0x28fc fs/ext4/inode.c:2763 do_writepages+0x2c4/0x50c mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x124/0x174 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_flush+0xc8/0x124 mm/filemap.c:454 ext4_convert_inline_data+0x138/0x4fc fs/ext4/inline.c:2105 ext4_page_mkwrite+0x194/0x10b0 fs/ext4/inode.c:6278 do_page_mkwrite+0x140/0x35c mm/memory.c:3009 wp_page_shared+0x14c/0x544 mm/memory.c:3358 do_wp_page+0xc88/0xed4 mm/memory.c:3508 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1520/0x3018 mm/memory.c:5292 __do_page_fault arch/arm64/mm/fault.c:499 [inline] do_page_fault+0x310/0x99c arch/arm64/mm/fault.c:583 do_mem_abort+0x70/0x198 arch/arm64/mm/fault.c:804 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:580 __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:217 [inline] clear_rseq_cs kernel/rseq.c:250 [inline] rseq_ip_fixup kernel/rseq.c:284 [inline] __rseq_handle_notify_resume+0x988/0x15cc kernel/rseq.c:322 rseq_handle_notify_resume include/linux/sched.h:2341 [inline] resume_user_mode_work include/linux/resume_user_mode.h:61 [inline] do_notify_resume+0x18d8/0x2c84 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 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 *** 4 locks held by syz.0.392/5822: #0: ffff0000d9e76d48 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff0000d9e76d48 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff0000d9e76d48 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x38/0x2e0 mm/memory.c:5382 #1: ffff0000de32e558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline] #1: ffff0000de32e558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1995 [inline] #1: ffff0000de32e558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x168/0x10b0 fs/ext4/inode.c:6273 #2: ffff0000e1b123b8 (mapping.invalidate_lock#2){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:813 [inline] #2: ffff0000e1b123b8 (mapping.invalidate_lock#2){++++}-{3:3}, at: ext4_page_mkwrite+0x18c/0x10b0 fs/ext4/inode.c:6276 #3: ffff0000de32cc18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1b0/0x28fc fs/ext4/inode.c:2717 stack backtrace: CPU: 1 PID: 5822 Comm: syz.0.392 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026 Call trace: dump_backtrace+0x1c4/0x1f0 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+0xf4/0x15c 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+0x264/0x2f8 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3830 [inline] __lock_acquire+0x2808/0x6634 kernel/locking/lockdep.c:5063 lock_acquire+0x20c/0x638 kernel/locking/lockdep.c:5676 down_write+0x5c/0x88 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1930 ext4_writepages+0x42c/0x28fc fs/ext4/inode.c:2763 do_writepages+0x2c4/0x50c mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x124/0x174 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_flush+0xc8/0x124 mm/filemap.c:454 ext4_convert_inline_data+0x138/0x4fc fs/ext4/inline.c:2105 ext4_page_mkwrite+0x194/0x10b0 fs/ext4/inode.c:6278 do_page_mkwrite+0x140/0x35c mm/memory.c:3009 wp_page_shared+0x14c/0x544 mm/memory.c:3358 do_wp_page+0xc88/0xed4 mm/memory.c:3508 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1520/0x3018 mm/memory.c:5292 __do_page_fault arch/arm64/mm/fault.c:499 [inline] do_page_fault+0x310/0x99c arch/arm64/mm/fault.c:583 do_mem_abort+0x70/0x198 arch/arm64/mm/fault.c:804 el1_abort+0x3c/0x5c arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0x50/0xac arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:580 __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:217 [inline] clear_rseq_cs kernel/rseq.c:250 [inline] rseq_ip_fixup kernel/rseq.c:284 [inline] __rseq_handle_notify_resume+0x988/0x15cc kernel/rseq.c:322 rseq_handle_notify_resume include/linux/sched.h:2341 [inline] resume_user_mode_work include/linux/resume_user_mode.h:61 [inline] do_notify_resume+0x18d8/0x2c84 arch/arm64/kernel/signal.c:1151 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x98/0x128 arch/arm64/kernel/entry-common.c:638 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585 EXT4-fs error (device loop0): ext4_mb_generate_buddy:1126: group 0, block bitmap and bg descriptor inconsistent: 25 vs 281 free clusters EXT4-fs (loop0): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop0): This should not happen!! Data will be lost EXT4-fs (loop0): Total free blocks count 0 EXT4-fs (loop0): Free/Dirty block details EXT4-fs (loop0): free_blocks=4096 EXT4-fs (loop0): dirty_blocks=64 EXT4-fs (loop0): Block reservation details EXT4-fs (loop0): i_reserved_data_blocks=4