Re: [sdl-qemu] [PATCH 1/1] No checks, dereferencing possible

[Peter Krempa <pkrempa@redhat.com>]

On Thu, Sep 14, 2023 at 09:44:16 +0000, Миронов Сергей Владимирович wrote:
> No checks, dereferencing possible.
> 
> 
> Return value of a function 'virDomainChrSourceDefNew'
> is dereferenced at qemu_command.c without checking
> for NULL, but it is usually checked for this function.

This description here doesn't make sense. You are checking the presence
of 'privateData' in 'virDomainVideoDef'.

> 
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> 
> Fixes: 1f85f0967b ("ci: jobs.sh: Add back '--no-suite syntax-check --print-errorlogs'")
> 
> Signed-off-by: Sergey Mironov <mironov@fintech.ru>
> 
> ---
> src/qemu/qemu_command.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
> index e84374b4cf..8d11972c88 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -4698,6 +4698,8 @@ qemuBuildVideoCommandLine(virCommand *cmd,
>              g_autofree char *name = g_strdup_printf("%s-vhost-user", video->info.alias);
>              qemuDomainChrSourcePrivate *chrsrcpriv = QEMU_DOMAIN_CHR_SOURCE_PRIVATE(chrsrc);
> 
> +           if (chrsrc == NULL)
> +                   return -1;

This addition doesn't make sense as it's dead code. The private data is
always allocated and checked that it's non-NULL in the qemu driver via
the callback in virDomainVideoDefNew.

Do you have a call trace that would prove me otherwise?