====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ vhost-4751/4786 is trying to acquire lock: ffff88807a7b9488 (&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: ffff8880746b94a0 (&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 __put_user_nocheck_2+0x3/0x11 vhost_put_used_flags drivers/vhost/vhost.c:970 [inline] vhost_update_used_flags+0x12e/0x270 drivers/vhost/vhost.c:1983 vhost_disable_notify+0xa9/0x1a0 drivers/vhost/vhost.c:2587 vhost_vsock_handle_tx_kick+0x14d/0xc60 drivers/vhost/vsock.c:512 vhost_worker+0x1f9/0x320 drivers/vhost/vhost.c:372 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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 *** 4 locks held by vhost-4751/4786: #0: ffff888062104c20 (&vq->mutex){+.+.}-{3:3}, at: vhost_vsock_handle_tx_kick+0xea/0xc60 drivers/vhost/vsock.c:504 #1: ffff88801eb64e28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline] #1: ffff88801eb64e28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298 #2: ffff88805a1f8558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 #3: ffff8880746b94a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142 stack backtrace: CPU: 1 PID: 4786 Comm: vhost-4751 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:__put_user_nocheck_2+0x3/0x11 Code: 00 00 48 39 d9 73 74 0f 01 cb 88 01 31 c9 0f 01 ca c3 90 90 90 90 90 90 48 bb ff ef ff ff ff 7f 00 00 48 39 d9 73 54 0f 01 cb <66> 89 01 31 c9 0f 01 ca c3 90 90 90 90 90 48 bb fd ef ff ff ff 7f RSP: 0018:ffffc90002fbfc58 EFLAGS: 00050202 RAX: 0000000000000001 RBX: 00002000000002c0 RCX: 00002000000002c0 RDX: ffffc90013c3a000 RSI: 0000000000000009 RDI: ffff888062104d56 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffff520005f7f51 R10: fffff520005f7f51 R11: 1ffff920005f7f50 R12: dffffc0000000000 R13: ffff888062104bb8 R14: ffff888062104bb0 R15: ffff8880621095b0 vhost_put_used_flags drivers/vhost/vhost.c:970 [inline] vhost_update_used_flags+0x12e/0x270 drivers/vhost/vhost.c:1983 vhost_disable_notify+0xa9/0x1a0 drivers/vhost/vhost.c:2587 vhost_vsock_handle_tx_kick+0x14d/0xc60 drivers/vhost/vsock.c:512 vhost_worker+0x1f9/0x320 drivers/vhost/vhost.c:372 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 48 39 d9 cmp %rbx,%rcx 5: 73 74 jae 0x7b 7: 0f 01 cb stac a: 88 01 mov %al,(%rcx) c: 31 c9 xor %ecx,%ecx e: 0f 01 ca clac 11: c3 ret 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 48 bb ff ef ff ff ff movabs $0x7fffffffefff,%rbx 1f: 7f 00 00 22: 48 39 d9 cmp %rbx,%rcx 25: 73 54 jae 0x7b 27: 0f 01 cb stac * 2a: 66 89 01 mov %ax,(%rcx) <-- trapping instruction 2d: 31 c9 xor %ecx,%ecx 2f: 0f 01 ca clac 32: c3 ret 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 48 rex.W 39: bb fd ef ff ff mov $0xffffeffd,%ebx 3e: ff (bad) 3f: 7f .byte 0x7f