Re: [PATCH-next] x86/kernel: Fix unchecked return value

[Borislav Petkov]

On Sat, May 15, 2021 at 09:22:12PM +0100, Khaled ROMDHANI wrote:
> From the coverity scan analysis, the return value from
> insn_decode_kernel is not checked. It is a macro constructed
> from the insn_decode function which may fail and return
> negative integer. Fix this by explicitly checking the
> return value.
> 
> Addresses-Coverity: ("Unchecked return value")
> Signed-off-by: Khaled ROMDHANI <khaledromdhani216@xxxxxxxxx>
> ---
>  arch/x86/kernel/jump_label.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/jump_label.c b/arch/x86/kernel/jump_label.c
> index a762dc1c615e..bf0ea003b6e7 100644
> --- a/arch/x86/kernel/jump_label.c
> +++ b/arch/x86/kernel/jump_label.c
> @@ -23,7 +23,7 @@ int arch_jump_entry_size(struct jump_entry *entry)
>  {
>  	struct insn insn = {};
>  
> -	insn_decode_kernel(&insn, (void *)jump_entry_code(entry));
> +	WARN_ON(insn_decode_kernel(&insn, (void *)jump_entry_code(entry)));

I don't think coverity is smart enough to notice...

>  	BUG_ON(insn.length != 2 && insn.length != 5);
	^^^^^^^^^^^^^

... this line.


-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette