====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc5-syzkaller-gc32f8dc5aaf9 #0 Not tainted ------------------------------------------------------ syz.5.347/8244 is trying to acquire lock: ffff0000fb4714a0 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_page_mkwrite+0x340/0xbf0 fs/ocfs2/mmap.c:142 but task is already holding lock: ffff0000d9834518 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults#4){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:52 [inline] __sb_start_write include/linux/fs.h:1783 [inline] sb_start_pagefault include/linux/fs.h:1948 [inline] ocfs2_page_mkwrite+0x1b0/0xbf0 fs/ocfs2/mmap.c:122 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x1b54/0x43a8 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1064/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:627 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:789 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #1 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xc4/0x124 mm/memory.c:7151 _inline_copy_to_user include/linux/uaccess.h:192 [inline] copy_to_user include/linux/uaccess.h:223 [inline] fiemap_fill_next_extent+0x17c/0x3f0 fs/ioctl.c:145 ocfs2_fiemap+0x648/0x9c4 fs/ocfs2/extent_map.c:806 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x1624/0x2218 fs/ioctl.c:840 __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __arm64_sys_ioctl+0xe4/0x1c4 fs/ioctl.c:892 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 -> #0 (&oi->ip_alloc_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1728/0x3058 kernel/locking/lockdep.c:5235 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5866 down_write+0x50/0xc0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x340/0xbf0 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x1b54/0x43a8 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1064/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:627 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:789 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600 other info that might help us debug this: Chain exists of: &oi->ip_alloc_sem --> &mm->mmap_lock --> sb_pagefaults#4 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#4); lock(&mm->mmap_lock); lock(sb_pagefaults#4); lock(&oi->ip_alloc_sem); *** DEADLOCK *** 2 locks held by syz.5.347/8244: #0: ffff0000d68eac50 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:203 [inline] #0: ffff0000d68eac50 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6346 [inline] #0: ffff0000d68eac50 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x38/0x2d8 mm/memory.c:6406 #1: ffff0000d9834518 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 stack backtrace: CPU: 0 UID: 0 PID: 8244 Comm: syz.5.347 Not tainted 6.15.0-rc5-syzkaller-gc32f8dc5aaf9 #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 dump_stack+0x1c/0x28 lib/dump_stack.c:129 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2079 check_noncircular+0x154/0x174 kernel/locking/lockdep.c:2211 check_prev_add kernel/locking/lockdep.c:3166 [inline] check_prevs_add kernel/locking/lockdep.c:3285 [inline] validate_chain kernel/locking/lockdep.c:3909 [inline] __lock_acquire+0x1728/0x3058 kernel/locking/lockdep.c:5235 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5866 down_write+0x50/0xc0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x340/0xbf0 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x138/0x2b8 mm/memory.c:3287 wp_page_shared mm/memory.c:3688 [inline] do_wp_page+0x1b54/0x43a8 mm/memory.c:3907 handle_pte_fault mm/memory.c:6013 [inline] __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1064/0x4cec mm/memory.c:6309 do_page_fault+0x598/0x1554 arch/arm64/mm/fault.c:690 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:919 el0_da+0x64/0x160 arch/arm64/kernel/entry-common.c:627 el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:789 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600