Re: [PATCH] clk/ti/adpll: allocate room for terminating null

From: Tony Lindgren
Date: Fri Sep 27 2019 - 11:23:20 EST


* Stephen Kitt <steve@xxxxxxx> [190927 15:13]:
> The buffer allocated in ti_adpll_clk_get_name doesn't account for the
> terminating null. This patch adds the extra byte, and switches to
> snprintf to avoid overflowing.
>
> Signed-off-by: Stephen Kitt <steve@xxxxxxx>
> ---
> drivers/clk/ti/adpll.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clk/ti/adpll.c b/drivers/clk/ti/adpll.c
> index fdfb90058504..27933c4e8a27 100644
> --- a/drivers/clk/ti/adpll.c
> +++ b/drivers/clk/ti/adpll.c
> @@ -196,12 +196,13 @@ static const char *ti_adpll_clk_get_name(struct ti_adpll_data *d,
> } else {
> const char *base_name = "adpll";
> char *buf;
> + size_t size = 8 + 1 + strlen(base_name) + 1 +
> + strlen(postfix) + 1;
>
> - buf = devm_kzalloc(d->dev, 8 + 1 + strlen(base_name) + 1 +
> - strlen(postfix), GFP_KERNEL);
> + buf = devm_kzalloc(d->dev, size, GFP_KERNEL);
> if (!buf)
> return NULL;
> - sprintf(buf, "%08lx.%s.%s", d->pa, base_name, postfix);
> + snprintf(buf, size, "%08lx.%s.%s", d->pa, base_name, postfix);
> name = buf;
> }
>

Thanks for catching this. Maybe just use devm_kasprintf() here?

Regards,

Tony