syzbot

======================================================
WARNING: possible circular locking dependency detected
5.15.189-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1/4289 is trying to acquire lock:
ffff88805edd0660 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142

but task is already holding lock:
ffff88802b942558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (sb_pagefaults#2){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1811 [inline]
       sb_start_pagefault include/linux/fs.h:1910 [inline]
       ocfs2_page_mkwrite+0x18a/0xad0 fs/ocfs2/mmap.c:122
       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

-> #3 (&mm->mmap_lock){++++}-{3:3}:
       __might_fault+0xb3/0x110 mm/memory.c:5357
       _copy_to_user+0x29/0x130 lib/usercopy.c:35
       copy_to_user include/linux/uaccess.h:200 [inline]
       fiemap_fill_next_extent+0x19d/0x360 fs/ioctl.c:144
       ocfs2_fiemap_inline fs/ocfs2/extent_map.c:725 [inline]
       ocfs2_fiemap+0x999/0xc40 fs/ocfs2/extent_map.c:762
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x1464/0x1de0 fs/ioctl.c:814
       __do_sys_ioctl fs/ioctl.c:872 [inline]
       __se_sys_ioctl+0x83/0x170 fs/ioctl.c:860
       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

-> #2 (&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:3014
       do_mount fs/namespace.c:3357 [inline]
       __do_sys_mount fs/namespace.c:3565 [inline]
       __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3542
       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

-> #1 (&osb->system_file_mutex){+.+.}-{3:3}:
       __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_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
       ocfs2_lock_allocators+0x2f7/0x5b0 fs/ocfs2/suballoc.c:2669
       ocfs2_write_begin_nolock+0x2216/0x4180 fs/ocfs2/aops.c:1741
       ocfs2_write_begin+0x1ab/0x300 fs/ocfs2/aops.c:1905
       generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
       __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
       ocfs2_file_write_iter+0x1578/0x1cf0 fs/ocfs2/file.c:2472
       call_write_iter include/linux/fs.h:2172 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0x712/0xd00 fs/read_write.c:594
       ksys_write+0x14d/0x250 fs/read_write.c:647
       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 (&oi->ip_alloc_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+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       down_write+0x38/0x60 kernel/locking/rwsem.c:1551
       ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142
       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

other info that might help us debug this:

Chain exists of:
  &oi->ip_alloc_sem --> &mm->mmap_lock --> sb_pagefaults#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_pagefaults#2);
                               lock(&mm->mmap_lock);
                               lock(sb_pagefaults#2);
  lock(&oi->ip_alloc_sem);

 *** DEADLOCK ***

2 locks held by syz.0.1/4289:
 #0: ffff88807dce5528 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dce5528 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffff88802b942558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922

stack backtrace:
CPU: 1 PID: 4289 Comm: syz.0.1 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 down_write+0x38/0x60 kernel/locking/rwsem.c:1551
 ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142
 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: 0033:0x7f1d88ea6209
Code: ff ff ff 01 64 48 8b 04 25 00 00 00 00 48 8d b8 c8 fe ff ff e8 58 59 0c 00 85 c0 75 10 48 8b 44 24 68 48 8b b4 24 98 00 00 00 <48> 89 30 64 f0 83 2c 25 90 ff ff ff 01 48 8b 84 24 80 00 00 00 48
RSP: 002b:00007ffeeb57f650 EFLAGS: 00010246
RAX: 00002000000015c0 RBX: 0000000000000002 RCX: ffffffffffffff7f
RDX: 33093e8793db5fd0 RSI: 0000200000000080 RDI: 00005555893b43c8
RBP: 00007f1d891f8da0 R08: 0000001b31120000 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000001 R12: 00007f1d891f709c
R13: 00007f1d891f7090 R14: fffffffffffffffe R15: 00007ffeeb57f760
 </TASK>