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

[Ingo Molnar <mingo@xxxxxxxxxx>]

* 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