loop0: detected capacity change from 32768 to 0
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
5.11.0-syzkaller #0 Not tainted
------------------------------------------------------
syz.0.15/4173 is trying to acquire lock:
ffff888019f78858 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x8a/0x160 mm/memory.c:5018

but task is already holding lock:
ffff88802ed0d8e0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_fiemap+0x1e9/0xa60 fs/ocfs2/extent_map.c:757

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&oi->ip_alloc_sem){++++}-{3:3}:
       lock_acquire kernel/locking/lockdep.c:5442 [inline]
       lock_acquire+0x1a8/0x730 kernel/locking/lockdep.c:5407
       down_write+0x8d/0x150 kernel/locking/rwsem.c:1406
       ocfs2_page_mkwrite+0x250/0xa00 fs/ocfs2/mmap.c:144
       do_page_mkwrite+0x18b/0x400 mm/memory.c:2714
       do_shared_fault mm/memory.c:4083 [inline]
       do_fault mm/memory.c:4151 [inline]
       handle_pte_fault mm/memory.c:4387 [inline]
       __handle_mm_fault mm/memory.c:4522 [inline]
       handle_mm_fault+0x230a/0x3ba0 mm/memory.c:4620
       do_user_addr_fault+0x2d3/0x930 arch/x86/mm/fault.c:1393
       handle_page_fault arch/x86/mm/fault.c:1450 [inline]
       exc_page_fault+0x61/0xc0 arch/x86/mm/fault.c:1506
       asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580

-> #1 (sb_pagefaults#2){.+.+}-{0:0}:
       lock_acquire kernel/locking/lockdep.c:5442 [inline]
       lock_acquire+0x1a8/0x730 kernel/locking/lockdep.c:5407
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1592 [inline]
       sb_start_pagefault include/linux/fs.h:1691 [inline]
       ocfs2_page_mkwrite+0x170/0xa00 fs/ocfs2/mmap.c:124
       do_page_mkwrite+0x18b/0x400 mm/memory.c:2714
       do_shared_fault mm/memory.c:4083 [inline]
       do_fault mm/memory.c:4151 [inline]
       handle_pte_fault mm/memory.c:4387 [inline]
       __handle_mm_fault mm/memory.c:4522 [inline]
       handle_mm_fault+0x230a/0x3ba0 mm/memory.c:4620
       do_user_addr_fault+0x2d3/0x930 arch/x86/mm/fault.c:1393
       handle_page_fault arch/x86/mm/fault.c:1450 [inline]
       exc_page_fault+0x61/0xc0 arch/x86/mm/fault.c:1506
       asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580

-> #0 (&mm->mmap_lock#2){++++}-{3:3}:
       check_prev_add+0x163/0x20f0 kernel/locking/lockdep.c:2868
       check_prevs_add kernel/locking/lockdep.c:2993 [inline]
       validate_chain kernel/locking/lockdep.c:3608 [inline]
       __lock_acquire+0x2872/0x35d0 kernel/locking/lockdep.c:4832
       lock_acquire kernel/locking/lockdep.c:5442 [inline]
       lock_acquire+0x1a8/0x730 kernel/locking/lockdep.c:5407
       __might_fault mm/memory.c:5019 [inline]
       __might_fault+0xe8/0x160 mm/memory.c:5004
       _copy_to_user+0x20/0xd0 lib/usercopy.c:28
       copy_to_user include/linux/uaccess.h:200 [inline]
       fiemap_fill_next_extent+0x18d/0x320 fs/ioctl.c:141
       ocfs2_fiemap+0x4cc/0xa60 fs/ocfs2/extent_map.c:798
       ioctl_fiemap fs/ioctl.c:216 [inline]
       do_vfs_ioctl+0x1fd/0xe10 fs/ioctl.c:705
       __do_sys_ioctl fs/ioctl.c:751 [inline]
       __se_sys_ioctl fs/ioctl.c:739 [inline]
       __x64_sys_ioctl+0xc5/0x190 fs/ioctl.c:739
       do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

other info that might help us debug this:

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

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

1 lock held by syz.0.15/4173:
 #0: ffff88802ed0d8e0 (&oi->ip_alloc_sem){++++}-{3:3}, at: ocfs2_fiemap+0x1e9/0xa60 fs/ocfs2/extent_map.c:757

stack backtrace:
CPU: 1 PID: 4173 Comm: syz.0.15 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x9a/0xcc lib/dump_stack.c:120
 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2117
 check_prev_add+0x163/0x20f0 kernel/locking/lockdep.c:2868
 check_prevs_add kernel/locking/lockdep.c:2993 [inline]
 validate_chain kernel/locking/lockdep.c:3608 [inline]
 __lock_acquire+0x2872/0x35d0 kernel/locking/lockdep.c:4832
 lock_acquire kernel/locking/lockdep.c:5442 [inline]
 lock_acquire+0x1a8/0x730 kernel/locking/lockdep.c:5407
 __might_fault mm/memory.c:5019 [inline]
 __might_fault+0xe8/0x160 mm/memory.c:5004
 _copy_to_user+0x20/0xd0 lib/usercopy.c:28
 copy_to_user include/linux/uaccess.h:200 [inline]
 fiemap_fill_next_extent+0x18d/0x320 fs/ioctl.c:141
 ocfs2_fiemap+0x4cc/0xa60 fs/ocfs2/extent_map.c:798
 ioctl_fiemap fs/ioctl.c:216 [inline]
 do_vfs_ioctl+0x1fd/0xe10 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:751 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0xc5/0x190 fs/ioctl.c:739
 do_syscall_64+0x34/0x50 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd31af1fff9
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:00007fd31a9a1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd31b0d7f80 RCX: 00007fd31af1fff9
RDX: 00000000200001c0 RSI: 00000000c020660b RDI: 0000000000000005
RBP: 00007fd31af92296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fd31b0d7f80 R15: 00007ffdc5fda738