Hello, syzbot found the following issue on: HEAD commit: e5eb28f6d1af Merge tag 'mm-nonmm-stable-2024-03-14-09-36' .. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=160dc26e180000 kernel config: https://syzkaller.appspot.com/x/.config?x=4ffb854606e658d dashboard link: https://syzkaller.appspot.com/bug?extid=49056626fe41e01f2ba7 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10f467b9180000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=173b7ac9180000 Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-e5eb28f6.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a5c7ad05d6b2/vmlinux-e5eb28f6.xz kernel image: https://storage.googleapis.com/syzbot-assets/531cb1917612/bzImage-e5eb28f6.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+49056626fe41e01f2ba7@xxxxxxxxxxxxxxxxxxxxxxxxx ============================================ WARNING: possible recursive locking detected 6.8.0-syzkaller-09791-ge5eb28f6d1af #0 Not tainted -------------------------------------------- syz-executor258/5169 is trying to acquire lock: ffff88802a6d23d0 (&vma->vm_lock->lock){++++}-{3:3}, at: uffd_move_lock mm/userfaultfd.c:1447 [inline] ffff88802a6d23d0 (&vma->vm_lock->lock){++++}-{3:3}, at: move_pages+0xbab/0x4970 mm/userfaultfd.c:1583 but task is already holding lock: ffff88802a6d2580 (&vma->vm_lock->lock){++++}-{3:3}, at: uffd_move_lock mm/userfaultfd.c:1445 [inline] ffff88802a6d2580 (&vma->vm_lock->lock){++++}-{3:3}, at: move_pages+0xb6f/0x4970 mm/userfaultfd.c:1583 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&vma->vm_lock->lock); lock(&vma->vm_lock->lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by syz-executor258/5169: #0: ffff888015086a20 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock include/linux/mmap_lock.h:146 [inline] #0: ffff888015086a20 (&mm->mmap_lock){++++}-{3:3}, at: uffd_move_lock mm/userfaultfd.c:1438 [inline] #0: ffff888015086a20 (&mm->mmap_lock){++++}-{3:3}, at: move_pages+0x8df/0x4970 mm/userfaultfd.c:1583 #1: ffff88802a6d2580 (&vma->vm_lock->lock){++++}-{3:3}, at: uffd_move_lock mm/userfaultfd.c:1445 [inline] #1: ffff88802a6d2580 (&vma->vm_lock->lock){++++}-{3:3}, at: move_pages+0xb6f/0x4970 mm/userfaultfd.c:1583 stack backtrace: CPU: 2 PID: 5169 Comm: syz-executor258 Not tainted 6.8.0-syzkaller-09791-ge5eb28f6d1af #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x20e6/0x3b30 kernel/locking/lockdep.c:5137 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1b1/0x540 kernel/locking/lockdep.c:5719 down_read+0x9a/0x330 kernel/locking/rwsem.c:1526 uffd_move_lock mm/userfaultfd.c:1447 [inline] move_pages+0xbab/0x4970 mm/userfaultfd.c:1583 userfaultfd_move fs/userfaultfd.c:2008 [inline] userfaultfd_ioctl+0x5e1/0x60e0 fs/userfaultfd.c:2126 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl fs/ioctl.c:890 [inline] __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x6d/0x75 RIP: 0033:0x7fd48da20329 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd1244f8e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffd1244fab8 RCX: 00007fd48da20329 RDX: 00000000200000c0 RSI: 00000000c028aa05 RDI: 0000000000000003 RBP: 00007fd48da93610 R08: 00007ffd1244fab8 R09: 00007ffd1244fab8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffd1244faa8 R14: 0000000000000001 R15: 0000000000000001 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
