loop4: detected capacity change from 0 to 2048 EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.4.654/7924 is trying to acquire lock: ffff0000f0c64b80 (&ei->xattr_sem){++++}-{4:4}, at: ext4_write_lock_xattr fs/ext4/xattr.h:157 [inline] ffff0000f0c64b80 (&ei->xattr_sem){++++}-{4:4}, at: ext4_destroy_inline_data+0x30/0x114 fs/ext4/inline.c:1805 but task is already holding lock: ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x16c/0x2d8 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+0x16c/0x2d8 fs/ext4/inode.c:3041 do_writepages+0x270/0x468 mm/page-writeback.c:2571 __writeback_single_inode+0x144/0x1808 fs/fs-writeback.c:1764 writeback_single_inode+0x3b8/0xaa0 fs/fs-writeback.c:1883 write_inode_now+0x170/0x208 fs/fs-writeback.c:2974 iput_final fs/inode.c:1950 [inline] iput+0x6bc/0xb90 fs/inode.c:2009 ext4_xattr_block_set+0x1aac/0x2188 fs/ext4/xattr.c:2153 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+0xb18/0x13a0 fs/ext4/xattr.c:2834 __ext4_expand_extra_isize+0x29c/0x370 fs/ext4/inode.c:6434 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6477 [inline] __ext4_mark_inode_dirty+0x3a4/0x810 fs/ext4/inode.c:6555 ext4_evict_inode+0x7a0/0xfc4 fs/ext4/inode.c:267 evict+0x4b8/0x740 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput+0x858/0xb90 fs/inode.c:2009 ext4_process_orphan+0x240/0x2b4 fs/ext4/orphan.c:358 ext4_orphan_cleanup+0x7b8/0xd30 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5701 [inline] ext4_fill_super+0x45a4/0x4d60 fs/ext4/super.c:5824 get_tree_bdev_flags+0x380/0x434 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+0x2a4/0x540 fs/namespace.c:3834 path_mount+0x5d0/0xa68 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+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 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+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 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+0x474/0x3ac8 fs/ext4/inode.c:2827 ext4_writepages+0x194/0x2d8 fs/ext4/inode.c:3042 do_writepages+0x270/0x468 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+0x138/0x4e4 fs/ext4/inline.c:1972 ext4_page_mkwrite+0x1cc/0xd48 fs/ext4/inode.c:6757 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3668 do_shared_fault mm/memory.c:5969 [inline] do_fault mm/memory.c:6031 [inline] do_pte_missing+0x5a4/0x28a4 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x1564/0x245c mm/memory.c:6718 do_page_fault+0x4a8/0xb64 arch/arm64/mm/fault.c:747 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:840 do_mem_abort+0x70/0x190 arch/arm64/mm/fault.c:980 el1_abort+0x50/0x74 arch/arm64/kernel/entry-common.c:326 el1h_64_sync_handler+0xdc/0x130 arch/arm64/kernel/entry-common.c:453 el1h_64_sync+0x6c/0x70 arch/arm64/kernel/entry.S:589 __arch_copy_to_user+0x190/0x240 arch/arm64/lib/copy_template.S:168 copy_page_to_iter+0x244/0x334 lib/iov_iter.c:374 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0x6a0/0xcac mm/filemap.c:2857 generic_file_read_iter+0x9c/0x344 mm/filemap.c:2998 ext4_file_read_iter+0x330/0x42c fs/ext4/file.c:-1 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x4ac/0x8e4 fs/read_write.c:574 ksys_read+0x12c/0x224 fs/read_write.c:717 __do_sys_read fs/read_write.c:726 [inline] __se_sys_read fs/read_write.c:724 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:724 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 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 *** 5 locks held by syz.4.654/7924: #0: ffff0000db3b9970 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x100/0x144 fs/file.c:1261 #1: ffff0000d5996bf8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:611 [inline] #1: ffff0000d5996bf8 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:441 [inline] #1: ffff0000d5996bf8 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x38/0x2c0 mm/mmap_lock.c:501 #2: ffff0000fc4fc508 (sb_pagefaults){.+.+}-{0:0}, at: percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] #2: ffff0000fc4fc508 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs/super.h:19 [inline] #2: ffff0000fc4fc508 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs/super.h:159 [inline] #2: ffff0000fc4fc508 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a0/0xd48 fs/ext4/inode.c:6752 #3: ffff0000f0c64fd0 (mapping.invalidate_lock#2){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #3: ffff0000f0c64fd0 (mapping.invalidate_lock#2){++++}-{4:4}, at: ext4_page_mkwrite+0x1c4/0xd48 fs/ext4/inode.c:6755 #4: ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: percpu_down_read include/linux/percpu-rwsem.h:77 [inline] #4: ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1811 [inline] #4: ffff0000fc4fac18 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x16c/0x2d8 fs/ext4/inode.c:3041 stack backtrace: CPU: 0 UID: 0 PID: 7924 Comm: syz.4.654 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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+0x1780/0x2f44 kernel/locking/lockdep.c:5237 lock_acquire+0x140/0x368 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+0x474/0x3ac8 fs/ext4/inode.c:2827 ext4_writepages+0x194/0x2d8 fs/ext4/inode.c:3042 do_writepages+0x270/0x468 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+0x138/0x4e4 fs/ext4/inline.c:1972 ext4_page_mkwrite+0x1cc/0xd48 fs/ext4/inode.c:6757 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3668 do_shared_fault mm/memory.c:5969 [inline] do_fault mm/memory.c:6031 [inline] do_pte_missing+0x5a4/0x28a4 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0x1564/0x245c mm/memory.c:6718 do_page_fault+0x4a8/0xb64 arch/arm64/mm/fault.c:747 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:840 do_mem_abort+0x70/0x190 arch/arm64/mm/fault.c:980 el1_abort+0x50/0x74 arch/arm64/kernel/entry-common.c:326 el1h_64_sync_handler+0xdc/0x130 arch/arm64/kernel/entry-common.c:453 el1h_64_sync+0x6c/0x70 arch/arm64/kernel/entry.S:589 __arch_copy_to_user+0x190/0x240 arch/arm64/lib/copy_template.S:168 (P) copy_page_to_iter+0x244/0x334 lib/iov_iter.c:374 copy_folio_to_iter include/linux/uio.h:204 [inline] filemap_read+0x6a0/0xcac mm/filemap.c:2857 generic_file_read_iter+0x9c/0x344 mm/filemap.c:2998 ext4_file_read_iter+0x330/0x42c fs/ext4/file.c:-1 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x4ac/0x8e4 fs/read_write.c:574 ksys_read+0x12c/0x224 fs/read_write.c:717 __do_sys_read fs/read_write.c:726 [inline] __se_sys_read fs/read_write.c:724 [inline] __arm64_sys_read+0x7c/0x90 fs/read_write.c:724 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:740 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:759 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 EXT4-fs error (device loop4): ext4_mb_generate_buddy:1317: group 0, block bitmap and bg descriptor inconsistent: 0 vs 150994969 free clusters EXT4-fs (loop4): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 32 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=32 EXT4-fs (loop4): Block reservation details EXT4-fs (loop4): i_reserved_data_blocks=2