Re: [PATCH] {linux,bsd}-user: Fail mmap() if size doesn't fit into host's size_t

[Richard Henderson]

On 1/26/24 06:07, Ilya Leoshkevich wrote:
> s390x's branch-relative-long test fails with the following error
> message on 32-bit hosts:
>
>      qemu-s390x: ../accel/tcg/user-exec.c:493: page_set_flags: Assertion `last 
> <= GUEST_ADDR_MAX' failed.
>
> The root cause is that the size passed to mmap() by this test does not
> fit into 32 bits and gets truncated. Since there is no chance for such
> mmap() to succeed, detect this condition and fail the mmap() right away.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> ---
>   bsd-user/mmap.c   | 4 ++++
>   linux-user/mmap.c | 4 ++++
>   2 files changed, 8 insertions(+)
>
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index 3ef11b28079..5dc327d0ad3 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -256,6 +256,10 @@ static abi_ulong mmap_find_vma_aligned(abi_ulong start, 
> abi_ulong size,
>   
>       size = HOST_PAGE_ALIGN(size);
>   
> +    if (size != (size_t)size) {
> +        return (abi_ulong)(-1);
> +    }
> +

I have this same fix in

20240102015808.132373-18-richard.henderson@linaro.org/">https://lore.kernel.org/qemu-devel/20240102015808.132373-18-richard.henderson@linaro.org/

so as far as that's concerned,

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

But perhaps you got cast your eye across the larger reorg,

20240102015808.132373-1-richard.henderson@linaro.org/">https://lore.kernel.org/qemu-devel/20240102015808.132373-1-richard.henderson@linaro.org/

?

r~