====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.3.80/4729 is trying to acquire lock: ffff88807a8cd488 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x1b5/0x760 fs/ocfs2/sysfile.c:101 but task is already holding lock: ffff88805e14cda0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}: down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498 ocfs2_read_virt_blocks+0x23f/0x8a0 fs/ocfs2/extent_map.c:976 ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline] ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline] ocfs2_find_entry+0x3d1/0x1f90 fs/ocfs2/dir.c:1091 ocfs2_find_files_on_disk+0xdb/0x2f0 fs/ocfs2/dir.c:1995 ocfs2_lookup_ino_from_name+0x4f/0xf0 fs/ocfs2/dir.c:2017 _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline] ocfs2_get_system_file_inode+0x319/0x760 fs/ocfs2/sysfile.c:112 ocfs2_init_global_system_inodes+0x316/0x650 fs/ocfs2/super.c:458 ocfs2_initialize_super fs/ocfs2/super.c:2279 [inline] ocfs2_fill_super+0x3dbf/0x4d80 fs/ocfs2/super.c:995 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:3025 do_mount fs/namespace.c:3368 [inline] __do_sys_mount fs/namespace.c:3576 [inline] __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3553 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 (&osb->system_file_mutex){+.+.}-{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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 ocfs2_get_system_file_inode+0x1b5/0x760 fs/ocfs2/sysfile.c:101 ocfs2_reserve_local_alloc_bits+0xfc/0x24c0 fs/ocfs2/localalloc.c:626 ocfs2_reserve_clusters_with_limit+0x1bb/0xba0 fs/ocfs2/suballoc.c:1162 ocfs2_convert_inline_data_to_extents+0x1c6/0x11f0 fs/ocfs2/alloc.c:7072 ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1564 [inline] ocfs2_write_begin_nolock+0x174d/0x4180 fs/ocfs2/aops.c:1671 __ocfs2_page_mkwrite fs/ocfs2/mmap.c:93 [inline] ocfs2_page_mkwrite+0x5be/0xad0 fs/ocfs2/mmap.c:144 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/0x43c0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 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] _copy_to_user+0xf0/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] __do_sys_newuname kernel/sys.c:1298 [inline] __se_sys_newuname+0x115/0x350 kernel/sys.c:1291 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(&ocfs2_file_ip_alloc_sem_key); lock(&osb->system_file_mutex); lock(&ocfs2_file_ip_alloc_sem_key); lock(&osb->system_file_mutex); *** DEADLOCK *** 3 locks held by syz.3.80/4729: #0: ffff88807d860828 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #0: ffff88807d860828 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298 #1: ffff888073fd8558 (sb_pagefaults#3){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 #2: ffff88805e14cda0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142 stack backtrace: CPU: 1 PID: 4729 Comm: syz.3.80 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 check_noncircular+0x274/0x310 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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 ocfs2_get_system_file_inode+0x1b5/0x760 fs/ocfs2/sysfile.c:101 ocfs2_reserve_local_alloc_bits+0xfc/0x24c0 fs/ocfs2/localalloc.c:626 ocfs2_reserve_clusters_with_limit+0x1bb/0xba0 fs/ocfs2/suballoc.c:1162 ocfs2_convert_inline_data_to_extents+0x1c6/0x11f0 fs/ocfs2/alloc.c:7072 ocfs2_try_to_write_inline_data fs/ocfs2/aops.c:1564 [inline] ocfs2_write_begin_nolock+0x174d/0x4180 fs/ocfs2/aops.c:1671 __ocfs2_page_mkwrite fs/ocfs2/mmap.c:93 [inline] ocfs2_page_mkwrite+0x5be/0xad0 fs/ocfs2/mmap.c:144 do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 wp_page_shared+0x16b/0x6d0 mm/memory.c:3259 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1eca/0x43c0 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357 handle_page_fault arch/x86/mm/fault.c:1445 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501 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:ffffc9000474fc00 EFLAGS: 00050202 RAX: ffffffff83dadb01 RBX: 0000000000000186 RCX: 0000000000000186 RDX: 0000000000000186 RSI: ffffc9000474fcf0 RDI: 0000200000000200 RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000005 R10: fffff520008e9fce R11: 0000000000000028 R12: 00007ffffffff000 R13: 0000200000000386 R14: ffffc9000474fcf0 R15: 0000200000000200 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] _copy_to_user+0xf0/0x130 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:200 [inline] __do_sys_newuname kernel/sys.c:1298 [inline] __se_sys_newuname+0x115/0x350 kernel/sys.c:1291 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: 0033:0x7f13eae9eba9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f13e9106038 EFLAGS: 00000246 ORIG_RAX: 000000000000003f RAX: ffffffffffffffda RBX: 00007f13eb0e5fa0 RCX: 00007f13eae9eba9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000200 RBP: 00007f13eaf21e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f13eb0e6038 R14: 00007f13eb0e5fa0 R15: 00007ffcc48cd058 ---------------- 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