====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.1.1177/11029 is trying to acquire lock: ffff0000f26a0a18 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff0000f26a0a18 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1805 but task is already holding lock: ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2dc fs/ext4/inode.c:3041 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+0x5c/0x294 include/linux/percpu-rwsem.h:53 percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ext4_writepages+0x170/0x2dc fs/ext4/inode.c:3041 do_writepages+0x284/0x47c mm/page-writeback.c:2571 __writeback_single_inode+0x140/0x1880 fs/fs-writeback.c:1764 writeback_single_inode+0x3b8/0xaa4 fs/fs-writeback.c:1883 write_inode_now+0x170/0x208 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput+0x6e8/0xbc0 fs/inode.c:2009 ext4_xattr_block_set+0x1460/0x21e8 fs/ext4/xattr.c:2206 ext4_xattr_move_to_block fs/ext4/xattr.c:2671 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2746 [inline] ext4_expand_extra_isize_ea+0xaf4/0x1384 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x2a4/0x378 fs/ext4/inode.c:6434 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline] __ext4_mark_inode_dirty+0x394/0x828 fs/ext4/inode.c:6555 ext4_evict_inode+0x798/0xfb8 fs/ext4/inode.c:267 evict+0x4c0/0x74c fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput+0x884/0xbc0 fs/inode.c:2009 ext4_process_orphan+0x24c/0x2c0 fs/ext4/orphan.c:358 ext4_orphan_cleanup+0x7d4/0xd20 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x4628/0x4e14 fs/ext4/super.c:5824 get_tree_bdev_flags+0x388/0x43c fs/super.c:1694 get_tree_bdev+0x2c/0x3c fs/super.c:1717 ext4_get_tree+0x28/0x38 fs/ext4/super.c:5856 vfs_get_tree+0x90/0x28c fs/super.c:1754 fc_mount+0x24/0xac fs/namespace.c:1193 do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x2a4/0x538 fs/namespace.c:3834 path_mount+0x5f0/0xa88 fs/namespace.c:4154 do_mount+0xe8/0x148 fs/namespace.c:4167 __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount fs/namespace.c:4360 [inline] __arm64_sys_mount+0x334/0x380 fs/namespace.c:4360 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 -> #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+0x17c0/0x2ebc kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868 down_write+0x50/0xc0 kernel/locking/rwsem.c:1625 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1805 ext4_do_writepages+0x3e4/0x3bc0 fs/ext4/inode.c:2827 ext4_writepages+0x198/0x2dc fs/ext4/inode.c:3042 do_writepages+0x284/0x47c mm/page-writeback.c:2571 filemap_writeback+0x230/0x2bc mm/filemap.c:388 filemap_flush_range mm/filemap.c:437 [inline] filemap_flush+0x30/0x40 mm/filemap.c:452 ext4_convert_inline_data+0x138/0x4e8 fs/ext4/inline.c:1972 ext4_page_mkwrite+0x1d0/0xd1c fs/ext4/inode.c:6757 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3684 wp_page_shared mm/memory.c:4085 [inline] do_wp_page+0x1270/0x4074 mm/memory.c:4304 handle_pte_fault mm/memory.c:6443 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0x123c/0x253c mm/memory.c:6734 do_page_fault+0x77c/0xb88 arch/arm64/mm/fault.c:704 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:980 el0_da+0x78/0x254 arch/arm64/kernel/entry-common.c:552 el0t_64_sync_handler+0x10c/0x148 arch/arm64/kernel/entry-common.c:758 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 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 *** 4 locks held by syz.1.1177/11029: #0: ffff0000cebdc1c8 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1c4/0x498 mm/mmap_lock.c:310 #1: ffff0000c4f12508 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #1: ffff0000c4f12508 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #1: ffff0000c4f12508 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #1: ffff0000c4f12508 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a4/0xd1c fs/ext4/inode.c:6752 #2: ffff0000f26a0e68 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #2: ffff0000f26a0e68 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_page_mkwrite+0x1c8/0xd1c fs/ext4/inode.c:6755 #3: ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #3: ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] #3: ffff0000da9eec18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2dc fs/ext4/inode.c:3041 stack backtrace: CPU: 1 UID: 0 PID: 11029 Comm: syz.1.1177 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/02/2026 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x328/0x330 kernel/locking/lockdep.c:2043 check_noncircular+0x158/0x174 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+0x17c0/0x2ebc kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x364 kernel/locking/lockdep.c:5868 down_write+0x50/0xc0 kernel/locking/rwsem.c:1625 ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1805 ext4_do_writepages+0x3e4/0x3bc0 fs/ext4/inode.c:2827 ext4_writepages+0x198/0x2dc fs/ext4/inode.c:3042 do_writepages+0x284/0x47c mm/page-writeback.c:2571 filemap_writeback+0x230/0x2bc mm/filemap.c:388 filemap_flush_range mm/filemap.c:437 [inline] filemap_flush+0x30/0x40 mm/filemap.c:452 ext4_convert_inline_data+0x138/0x4e8 fs/ext4/inline.c:1972 ext4_page_mkwrite+0x1d0/0xd1c fs/ext4/inode.c:6757 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3684 wp_page_shared mm/memory.c:4085 [inline] do_wp_page+0x1270/0x4074 mm/memory.c:4304 handle_pte_fault mm/memory.c:6443 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0x123c/0x253c mm/memory.c:6734 do_page_fault+0x77c/0xb88 arch/arm64/mm/fault.c:704 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:980 el0_da+0x78/0x254 arch/arm64/kernel/entry-common.c:552 el0t_64_sync_handler+0x10c/0x148 arch/arm64/kernel/entry-common.c:758 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 EXT4-fs error (device loop1): ext4_mb_generate_buddy:1317: group 0, block bitmap and bg descriptor inconsistent: 25 vs 281 free clusters EXT4-fs (loop1): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop1): This should not happen!! Data will be lost EXT4-fs (loop1): Total free blocks count 0 EXT4-fs (loop1): Free/Dirty block details EXT4-fs (loop1): free_blocks=4096 EXT4-fs (loop1): dirty_blocks=16 EXT4-fs (loop1): Block reservation details EXT4-fs (loop1): i_reserved_data_blocks=1