Arithmetic overflow in `munmap` when length is too large

[nuczyc]

Describe the bug

The kernel panics with an "attempt to add with overflow" error when the munmap system call is invoked with a length of 0xffffffffffffffff (UINT64_MAX).

ruxos/api/ruxos_posix_api/src/imp/mmap/api.rs

Line 108 in 74cb02c

let end = VirtAddr::from(start + len).align_up_4k().as_usize();

To Reproduce

1. Compile the program and run.

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <unistd.h>

int main()
{
    void *addr = mmap(NULL, 4096, 0x3, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
    munmap(addr, 0xffffffffffffffff);

    return 0;
}

2.features.txt

alloc
paging
net
multitask
irq
fs

Environment

• RuxOS version:[Merge pull request #219 from syswonder/dev · syswonder/ruxos@32a8fe8](32a8fe8)

Logs

SeaBIOS (version 1.16.3-debian-1.16.3-2)


iPXE (https://ipxe.org) 00:03.0 CA00 PCI2.10 PnP PMM+7EFCA9F0+7EF0A9F0 CA00
                                                                               


Booting from ROM..
Initialize IDT & GDT...

8888888b.                     .d88888b.   .d8888b.
888   Y88b                   d88P" "Y88b d88P  Y88b
888    888                   888     888 Y88b.
888   d88P 888  888 888  888 888     888  "Y888b.
8888888P"  888  888 `Y8bd8P' 888     888     "Y88b.
888 T88b   888  888   X88K   888     888       "888
888  T88b  Y88b 888 .d8""8b. Y88b. .d88P Y88b  d88P
888   T88b  "Y88888 888  888  "Y88888P"   "Y8888P"

arch = x86_64
platform = x86_64-qemu-q35
target = x86_64-unknown-none
smp = 1
build_mode = debug
log_level = warn

[1769077952.211025 0 axfs_ramfs::dir:68] AlreadyExists sys
[1769077952.213594 0:1 ruxruntime::lang_items:14] panicked at api/ruxos_posix_api/src/imp/mmap/api.rs:108:34:
attempt to add with overflow