Re: [PATCH RESEND] staging: nvec: use strcmp() instead of strncmp() with magic length

Thierry Reding <[email protected]> Mon, 27 Jul 2026 17:58:20 +0200

Newsgroups	org.kernel.vger.linux-tegra,dev.linux.lists.linux-staging
Message-ID	<amd-EkmT_H1xlm7Q@orome>

On Thu, Jul 23, 2026 at 07:18:23PM +0300, Artem Lytkin wrote:
> Replace strncmp() with a hardcoded length of 30 with strcmp().
> The bat_type string is already null-terminated (set two lines above),
> so strncmp() with an arbitrary length is misleading and functionally
> equivalent to strcmp().
> 
> Signed-off-by: Artem Lytkin <[email protected]>
> ---
>  drivers/staging/nvec/nvec_power.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

I don't really see a point in this. strncmp() doesn't do any harm and it
isn't misleading either. It's just very explicit that it should never
check more than those 30 characters that can fit into the type string.

Technically res->length could be larger than 30, in which case the
memcpy() might copy more than those 30. Judging by the nvec core code we
never sanity check the length, so even that memcpy() could be entirely
wrong.

Either way, this change by itself doesn't look useful.

Thierry

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