====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.802/8238 is trying to acquire lock: ffff888053a35108 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff888053a35108 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1922 but task is already holding lock: ffff8880554b2c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 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+0x44/0x1a0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 __writeback_single_inode+0x153/0x1170 fs/fs-writeback.c:1622 writeback_single_inode+0x3d2/0x8e0 fs/fs-writeback.c:1743 write_inode_now+0x17f/0x210 fs/fs-writeback.c:2786 iput_final fs/inode.c:1821 [inline] iput+0x643/0x9c0 fs/inode.c:1860 ext4_xattr_block_set+0x2487/0x2fe0 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+0xfca/0x1d40 fs/ext4/xattr.c:2776 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:6003 ext4_try_to_expand_extra_isize fs/ext4/inode.c:6046 [inline] __ext4_mark_inode_dirty+0x478/0x760 fs/ext4/inode.c:6124 ext4_evict_inode+0xa67/0x10e0 fs/ext4/inode.c:281 evict+0x4b6/0x8b0 fs/inode.c:705 ext4_orphan_cleanup+0xc32/0x1470 fs/ext4/orphan.c:472 __ext4_fill_super fs/ext4/super.c:5574 [inline] ext4_fill_super+0x6f0c/0x78f0 fs/ext4/super.c:5693 get_tree_bdev+0x3e6/0x610 fs/super.c:1366 vfs_get_tree+0x88/0x270 fs/super.c:1573 do_new_mount+0x247/0xa40 fs/namespace.c:3078 do_mount fs/namespace.c:3421 [inline] __do_sys_mount fs/namespace.c:3629 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 down_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1922 ext4_writepages+0x599/0x2e70 fs/ext4/inode.c:2763 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x11e/0x180 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_flush+0xe0/0x140 mm/filemap.c:454 ext4_convert_inline_data+0x186/0x5b0 fs/ext4/inline.c:2097 ext4_page_mkwrite+0x1c4/0x10d0 fs/ext4/inode.c:6278 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 wp_page_shared+0x167/0x370 mm/memory.c:3358 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 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.3.802/8238: #0: ffff88807f6f88d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807f6f88d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5320 [inline] #0: ffff88807f6f88d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5382 #1: ffff88807761c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1891 [inline] #1: ffff88807761c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1995 [inline] #1: ffff88807761c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x192/0x10d0 fs/ext4/inode.c:6273 #2: ffff888053a355e0 (mapping.invalidate_lock#2){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:813 [inline] #2: ffff888053a355e0 (mapping.invalidate_lock#2){++++}-{3:3}, at: ext4_page_mkwrite+0x1bc/0x10d0 fs/ext4/inode.c:6276 #3: ffff8880554b2c18 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x213/0x2e70 fs/ext4/inode.c:2717 stack backtrace: CPU: 0 PID: 8238 Comm: syz.3.802 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2c92/0x7bd0 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 down_write+0x36/0x60 kernel/locking/rwsem.c:1573 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1922 ext4_writepages+0x599/0x2e70 fs/ext4/inode.c:2763 do_writepages+0x3c6/0x640 mm/page-writeback.c:2491 filemap_fdatawrite_wbc+0x11e/0x180 mm/filemap.c:388 __filemap_fdatawrite_range mm/filemap.c:421 [inline] __filemap_fdatawrite mm/filemap.c:427 [inline] filemap_flush+0xe0/0x140 mm/filemap.c:454 ext4_convert_inline_data+0x186/0x5b0 fs/ext4/inline.c:2097 ext4_page_mkwrite+0x1c4/0x10d0 fs/ext4/inode.c:6278 do_page_mkwrite+0x16b/0x5c0 mm/memory.c:3009 wp_page_shared+0x167/0x370 mm/memory.c:3358 handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5171 [inline] handle_mm_fault+0x1b1b/0x3d40 mm/memory.c:5292 do_user_addr_fault+0x58e/0xb20 arch/x86/mm/fault.c:1338 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fbce376bceb Code: fa 10 73 2d 83 fa 08 73 46 83 fa 04 73 16 83 fa 01 7c 10 8a 0e 74 0a 0f b7 74 16 fe 66 89 74 17 fe 88 0f c3 8b 4c 16 fc 8b 36 <89> 4c 17 fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 RSP: 002b:00007ffede6aca78 EFLAGS: 00010202 RAX: 0000200000000780 RBX: 0000000000000004 RCX: 0000000000347478 RDX: 0000000000000005 RSI: 0000000034747865 RDI: 0000200000000780 RBP: fffffffffffffffe R08: 0000001b2ef20000 R09: 0000000000000001 R10: 7ffffffffffffffa R11: 0000000000000009 R12: 00007ffede6acba0 R13: 00007fbce3a15fac R14: 000000000006269a R15: 00007fbce3a15fa0 EXT4-fs error (device loop3): ext4_mb_generate_buddy:1126: group 0, block bitmap and bg descriptor inconsistent: 25 vs 281 free clusters EXT4-fs (loop3): Delayed block allocation failed for inode 15 at logical offset 0 with max blocks 1 with error 28 EXT4-fs (loop3): This should not happen!! Data will be lost EXT4-fs (loop3): Total free blocks count 0 EXT4-fs (loop3): Free/Dirty block details EXT4-fs (loop3): free_blocks=4096 EXT4-fs (loop3): dirty_blocks=16 EXT4-fs (loop3): Block reservation details EXT4-fs (loop3): i_reserved_data_blocks=1