loop1: detected capacity change from 0 to 2048 EXT4-fs (loop1): mounted filesystem without journal. Opts: delalloc,noload,acl,mb_optimize_scan=0x0000000000000001,,errors=continue. Quota mode: none. ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.1.157/4908 is trying to acquire lock: ffff888074553c98 (&ei->xattr_sem){++++}-{3:3}, at: ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ffff888074553c98 (&ei->xattr_sem){++++}-{3:3}, at: ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1900 but task is already holding lock: ffff888148018c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 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+0x46/0x1b0 include/linux/percpu-rwsem.h:51 ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 __writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1657 writeback_single_inode+0x3cb/0x8e0 fs/fs-writeback.c:1770 write_inode_now+0x23b/0x2c0 fs/fs-writeback.c:2817 iput_final fs/inode.c:1756 [inline] iput+0x5ab/0x8a0 fs/inode.c:1795 ext4_xattr_set_entry+0x34f4/0x3ea0 fs/ext4/xattr.c:1825 ext4_xattr_block_set+0x4fd/0x2d20 fs/ext4/xattr.c:1924 ext4_xattr_move_to_block fs/ext4/xattr.c:2618 [inline] ext4_xattr_make_inode_space fs/ext4/xattr.c:2693 [inline] ext4_expand_extra_isize_ea+0xf3f/0x19b0 fs/ext4/xattr.c:2781 __ext4_expand_extra_isize+0x301/0x3e0 fs/ext4/inode.c:5924 ext4_try_to_expand_extra_isize fs/ext4/inode.c:5967 [inline] __ext4_mark_inode_dirty+0x469/0x700 fs/ext4/inode.c:6045 ext4_evict_inode+0xa8d/0x1090 fs/ext4/inode.c:284 evict+0x4c9/0x8d0 fs/inode.c:647 ext4_orphan_cleanup+0xad2/0x1320 fs/ext4/orphan.c:472 ext4_fill_super+0x8d6e/0x94f0 fs/ext4/super.c:5006 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 do_mount fs/namespace.c:3377 [inline] __do_sys_mount fs/namespace.c:3585 [inline] __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 -> #0 (&ei->xattr_sem){++++}-{3:3}: check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1900 ext4_writepages+0x670/0x2df0 fs/ext4/inode.c:2737 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400 __filemap_fdatawrite_range mm/filemap.c:433 [inline] __filemap_fdatawrite mm/filemap.c:439 [inline] filemap_flush+0xd4/0x130 mm/filemap.c:466 ext4_convert_inline_data+0x18b/0x5f0 fs/ext4/inline.c:2076 ext4_page_mkwrite+0x1df/0x1250 fs/ext4/inode.c:6199 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1d87/0x4410 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:205 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] _copy_to_iter+0x318/0x1180 lib/iov_iter.c:669 copy_to_iter include/linux/uio.h:155 [inline] get_random_bytes_user+0x1cc/0x3d0 drivers/char/random.c:474 __do_sys_getrandom drivers/char/random.c:1242 [inline] __se_sys_getrandom drivers/char/random.c:1215 [inline] __x64_sys_getrandom+0x1c2/0x2a0 drivers/char/random.c:1215 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 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.1.157/4908: #0: ffff88807b884e28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117 #1: ffff88814801c558 (sb_pagefaults){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1811 [inline] #1: ffff88814801c558 (sb_pagefaults){.+.+}-{0:0}, at: sb_start_pagefault include/linux/fs.h:1910 [inline] #1: ffff88814801c558 (sb_pagefaults){.+.+}-{0:0}, at: ext4_page_mkwrite+0x1a5/0x1250 fs/ext4/inode.c:6194 #2: ffff888074554160 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:842 [inline] #2: ffff888074554160 (mapping.invalidate_lock){++++}-{3:3}, at: ext4_page_mkwrite+0x1d2/0x1250 fs/ext4/inode.c:6197 #3: ffff888148018c58 (&sbi->s_writepages_rwsem){.+.+}-{0:0}, at: ext4_writepages+0x20f/0x2df0 fs/ext4/inode.c:2691 stack backtrace: CPU: 1 PID: 4908 Comm: syz.1.157 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133 check_prev_add kernel/locking/lockdep.c:3053 [inline] check_prevs_add kernel/locking/lockdep.c:3172 [inline] validate_chain kernel/locking/lockdep.c:3788 [inline] __lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623 down_write+0x38/0x60 kernel/locking/rwsem.c:1551 ext4_write_lock_xattr fs/ext4/xattr.h:158 [inline] ext4_destroy_inline_data+0x24/0xe0 fs/ext4/inline.c:1900 ext4_writepages+0x670/0x2df0 fs/ext4/inode.c:2737 do_writepages+0x476/0x6e0 mm/page-writeback.c:2386 filemap_fdatawrite_wbc+0x1eb/0x240 mm/filemap.c:400 __filemap_fdatawrite_range mm/filemap.c:433 [inline] __filemap_fdatawrite mm/filemap.c:439 [inline] filemap_flush+0xd4/0x130 mm/filemap.c:466 ext4_convert_inline_data+0x18b/0x5f0 fs/ext4/inline.c:2076 ext4_page_mkwrite+0x1df/0x1250 fs/ext4/inode.c:6199 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 do_shared_fault mm/memory.c:4328 [inline] do_fault mm/memory.c:4396 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1d87/0x4410 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 89 d1 83 f8 RSP: 0018:ffffc900034cfb38 EFLAGS: 00050246 RAX: ffffffff83e1c601 RBX: 0000000000000040 RCX: 0000000000000040 RDX: 0000000000000040 RSI: ffffc900034cfd40 RDI: 0000200000000240 RBP: ffffc900034cfc90 R08: ffffc900034cfd7f R09: 1ffff92000699faf R10: dffffc0000000000 R11: fffff52000699fb0 R12: ffffc900034cfd40 R13: dffffc00000000ff R14: 0000200000000240 R15: 0000000000000000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline] copyout lib/iov_iter.c:157 [inline] _copy_to_iter+0x318/0x1180 lib/iov_iter.c:669 copy_to_iter include/linux/uio.h:155 [inline] get_random_bytes_user+0x1cc/0x3d0 drivers/char/random.c:474 __do_sys_getrandom drivers/char/random.c:1242 [inline] __se_sys_getrandom drivers/char/random.c:1215 [inline] __x64_sys_getrandom+0x1c2/0x2a0 drivers/char/random.c:1215 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fd08ab07dd9 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:00007fd088d61028 EFLAGS: 00000246 ORIG_RAX: 000000000000013e RAX: ffffffffffffffda RBX: 00007fd08ad80fa0 RCX: 00007fd08ab07dd9 RDX: 0100000000000001 RSI: 000000000000011e RDI: 0000200000000240 RBP: 00007fd08ab9dd69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd08ad81038 R14: 00007fd08ad80fa0 R15: 00007fffd98d7f08 EXT4-fs error (device loop1): ext4_mb_generate_buddy:1176: group 0, block bitmap and bg descriptor inconsistent: 0 vs 150994969 free clusters EXT4-fs (loop1): Delayed block allocation failed for inode 18 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=2415919504 EXT4-fs (loop1): dirty_blocks=16 EXT4-fs (loop1): Block reservation details EXT4-fs (loop1): i_reserved_data_blocks=1 ---------------- Code disassembly (best guess): 0: 89 d1 mov %edx,%ecx 2: c1 e9 03 shr $0x3,%ecx 5: 83 e2 07 and $0x7,%edx 8: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) b: 89 d1 mov %edx,%ecx d: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) f: 31 c0 xor %eax,%eax 11: 0f 01 ca clac 14: c3 ret 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 0f 01 cb stac 1f: 83 fa 40 cmp $0x40,%edx 22: 0f 82 70 ff ff ff jb 0xffffff98 28: 89 d1 mov %edx,%ecx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 31 c0 xor %eax,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 89 d1 mov %edx,%ecx 3e: 83 .byte 0x83 3f: f8 clc