Re: [PATCH] x86/boot: Check if the input parameter (buffer) of the function is a null pointer

From: Ingo Molnar
Date: Sat Jan 07 2023 - 05:41:04 EST



* Liam Ni <zhiguangni01@xxxxxxxxx> wrote:

> If the variable buffer is a null pointer, it may cause the kernel to crash.
>
> Signed-off-by: Liam Ni <zhiguangni01@xxxxxxxxx>
> ---
> arch/x86/boot/cmdline.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c
> index 21d56ae83cdf..d0809f66054c 100644
> --- a/arch/x86/boot/cmdline.c
> +++ b/arch/x86/boot/cmdline.c
> @@ -39,7 +39,7 @@ int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *b
> st_bufcpy /* Copying this to buffer */
> } state = st_wordstart;
>
> - if (!cmdline_ptr)
> + if (!cmdline_ptr || buffer == NULL)
> return -1; /* No command line */

Can this ever happen?

Thanks,

Ingo