Re: [PATCH] linux-user: permit sendto() with NULL buf and 0 len

[Richard Henderson <richard.henderson@linaro.org>]

On 10/28/25 15:20, Peter Maydell wrote:
> If you pass sendto() a NULL buffer, this is usually an error
> (causing an EFAULT return); however if you pass a 0 length then
> we should not try to validate the buffer provided. Instead we
> skip the copying of the user data and possible processing
> through fd_trans_target_to_host_data, and call the host syscall
> with NULL, 0.
> 
> (unlock_user() permits a NULL buffer pointer for "do nothing"
> so we don't need to special case the unlock code.)
> 
> Cc:qemu-stable@nongnu.org
> Resolves:https://gitlab.com/qemu-project/qemu/-/issues/3102
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   linux-user/syscall.c | 25 ++++++++++++++-----------
>   1 file changed, 14 insertions(+), 11 deletions(-)

Queued, thanks.

r~