====================================================== WARNING: possible circular locking dependency detected 5.15.185-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.78/4640 is trying to acquire lock: ffff88805f0594a0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_page_mkwrite+0x2ce/0xad0 fs/ocfs2/mmap.c:142 but task is already holding lock: ffff888079770558 (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: -> #2 (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 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+0x1d4b/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 -> #1 (&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 -> #0 (&ocfs2_file_ip_alloc_sem_key){++++}-{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 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+0x1d4b/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: &ocfs2_file_ip_alloc_sem_key --> &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(&ocfs2_file_ip_alloc_sem_key); *** DEADLOCK *** 2 locks held by syz.1.78/4640: #0: ffff88807e48b228 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock+0x1c/0x50 include/linux/mmap_lock.h:117 #1: ffff888079770558 (sb_pagefaults#2){.+.+}-{0:0}, at: do_page_mkwrite+0x168/0x3c0 mm/memory.c:2922 stack backtrace: CPU: 1 PID: 4640 Comm: syz.1.78 Not tainted 5.15.185-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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 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 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+0x1d4b/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: 0033:0x7f0d4ab11698 Code: fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 c5 RSP: 002b:00007fff8e1ed8a8 EFLAGS: 00010202 RAX: 0000200000000380 RBX: 0000000000000004 RCX: 0100000000000000 RDX: 000000000000000c RSI: 0000000000001f00 RDI: 0000200000000380 RBP: 00007f0d4ad72ba0 R08: 00007f0d4a9bb000 R09: 0000000000000018 R10: 0000000000000000 R11: 0000000000000000 R12: 00007f0d4ad70fac R13: 00007f0d4ad70fa0 R14: fffffffffffffffe R15: 00007fff8e1ed9c0