====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc1-syzkaller-00101-g27605c8c0f69 #0 Not tainted ------------------------------------------------------ syz.3.956/14927 is trying to acquire lock: ffff8880528a6a20 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 but task is already holding lock: ffff8880303f6520 (sb_pagefaults#11){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3378 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_pagefaults#11){.+.+}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline] __sb_start_write include/linux/fs.h:1793 [inline] sb_start_pagefault include/linux/fs.h:1958 [inline] ocfs2_page_mkwrite+0x1da/0xc40 fs/ocfs2/mmap.c:122 do_page_mkwrite+0x14a/0x310 mm/memory.c:3378 do_shared_fault mm/memory.c:5686 [inline] do_fault mm/memory.c:5748 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x1a60/0x5620 mm/memory.c:6232 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 __put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:97 epoll_put_uevent include/linux/eventpoll.h:85 [inline] ep_send_events fs/eventpoll.c:1910 [inline] ep_try_send_events+0x784/0xf40 fs/eventpoll.c:1993 ep_poll fs/eventpoll.c:2058 [inline] do_epoll_wait+0x53f/0xf40 fs/eventpoll.c:2532 __do_sys_epoll_wait fs/eventpoll.c:2540 [inline] __se_sys_epoll_wait fs/eventpoll.c:2535 [inline] __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2535 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&mm->mmap_lock){++++}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __might_fault+0xcc/0x130 mm/memory.c:6991 _inline_copy_to_user include/linux/uaccess.h:192 [inline] _copy_to_user+0x2c/0xb0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] fiemap_fill_next_extent+0x1c0/0x390 fs/ioctl.c:145 ocfs2_fiemap+0x888/0xc90 fs/ocfs2/extent_map.c:806 ioctl_fiemap fs/ioctl.c:220 [inline] do_vfs_ioctl+0x16d3/0x1990 fs/ioctl.c:841 __do_sys_ioctl fs/ioctl.c:905 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x14a/0x310 mm/memory.c:3378 do_shared_fault mm/memory.c:5686 [inline] do_fault mm/memory.c:5748 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x1a60/0x5620 mm/memory.c:6232 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 __put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:97 epoll_put_uevent include/linux/eventpoll.h:85 [inline] ep_send_events fs/eventpoll.c:1910 [inline] ep_try_send_events+0x784/0xf40 fs/eventpoll.c:1993 ep_poll fs/eventpoll.c:2058 [inline] do_epoll_wait+0x53f/0xf40 fs/eventpoll.c:2532 __do_sys_epoll_wait fs/eventpoll.c:2540 [inline] __se_sys_epoll_wait fs/eventpoll.c:2535 [inline] __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2535 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &ocfs2_file_ip_alloc_sem_key --> &mm->mmap_lock --> sb_pagefaults#11 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#11); lock(&mm->mmap_lock); lock(sb_pagefaults#11); lock(&ocfs2_file_ip_alloc_sem_key); *** DEADLOCK *** 3 locks held by syz.3.956/14927: #0: ffff8880327af068 (&ep->mtx){+.+.}-{4:4}, at: ep_send_events fs/eventpoll.c:1869 [inline] #0: ffff8880327af068 (&ep->mtx){+.+.}-{4:4}, at: ep_try_send_events+0x197/0xf40 fs/eventpoll.c:1993 #1: ffff8880223cd5e0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:431 [inline] #1: ffff8880223cd5e0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:188 [inline] #1: ffff8880223cd5e0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x32/0x300 mm/mmap_lock.c:248 #2: ffff8880303f6520 (sb_pagefaults#11){.+.+}-{0:0}, at: do_page_mkwrite+0x14a/0x310 mm/memory.c:3378 stack backtrace: CPU: 1 UID: 0 PID: 14927 Comm: syz.3.956 Not tainted 6.16.0-rc1-syzkaller-00101-g27605c8c0f69 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2046 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2178 check_prev_add kernel/locking/lockdep.c:3168 [inline] check_prevs_add kernel/locking/lockdep.c:3287 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3911 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1577 ocfs2_page_mkwrite+0x2ff/0xc40 fs/ocfs2/mmap.c:142 do_page_mkwrite+0x14a/0x310 mm/memory.c:3378 do_shared_fault mm/memory.c:5686 [inline] do_fault mm/memory.c:5748 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x1a60/0x5620 mm/memory.c:6232 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401 do_user_addr_fault+0x764/0x1390 arch/x86/mm/fault.c:1387 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x76/0xf0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104 Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 97 31 03 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000ad77ab8 EFLAGS: 00050246 RAX: 0000000000000004 RBX: ffff888078ebad2c RCX: 0000200000001f80 RDX: ffff88802ee03c00 RSI: 0000000000000004 RDI: ffff888078ebad33 RBP: ffffc9000ad77bf0 R08: ffff8880795d2f67 R09: 1ffff1100f2ba5ec R10: dffffc0000000000 R11: ffffed100f2ba5ed R12: ffff888078ebad28 R13: 0000200000001f80 R14: ffff888078ebacd8 R15: 0000000000000000 epoll_put_uevent include/linux/eventpoll.h:85 [inline] ep_send_events fs/eventpoll.c:1910 [inline] ep_try_send_events+0x784/0xf40 fs/eventpoll.c:1993 ep_poll fs/eventpoll.c:2058 [inline] do_epoll_wait+0x53f/0xf40 fs/eventpoll.c:2532 __do_sys_epoll_wait fs/eventpoll.c:2540 [inline] __se_sys_epoll_wait fs/eventpoll.c:2535 [inline] __x64_sys_epoll_wait+0x1be/0x210 fs/eventpoll.c:2535 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbfd458e929 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:00007fbfd539e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 00007fbfd47b5fa0 RCX: 00007fbfd458e929 RDX: 0000000000000001 RSI: 0000200000001f80 RDI: 0000000000000004 RBP: 00007fbfd4610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000d R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbfd47b5fa0 R15: 00007ffcae62e588 ---------------- Code disassembly (best guess): 0: d9 0f (bad) (%rdi) 2: 01 cb add %ecx,%ebx 4: 89 01 mov %eax,(%rcx) 6: 31 c9 xor %ecx,%ecx 8: 0f 01 ca clac b: e9 97 31 03 00 jmp 0x331a7 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 90 nop 24: 90 nop 25: 90 nop 26: 90 nop 27: 0f 01 cb stac * 2a: 89 01 mov %eax,(%rcx) <-- trapping instruction 2c: 31 c9 xor %ecx,%ecx 2e: 0f 01 ca clac 31: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: 90 nop 37: 90 nop 38: 90 nop 39: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop