Use strnlen() instead of strlen() on the algorithm and coefficient name
string arrays in V1 wmfw files.

In V1 wmfw files the name is a NUL-terminated string in a fixed-size
array. cs_dsp should protect against overrunning the array if the NUL
terminator is missing.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Fixes: f6bc909e7673 ("firmware: cs_dsp: add driver to support firmware loading on Cirrus Logic DSPs")
---
 drivers/firmware/cirrus/cs_dsp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
index 16484ab9b09d..8a347b938406 100644
--- a/drivers/firmware/cirrus/cs_dsp.c
+++ b/drivers/firmware/cirrus/cs_dsp.c
@@ -1183,4 +1183,4 @@ static int cs_dsp_coeff_parse_alg(struct cs_dsp *dsp,
 		blk->id = le32_to_cpu(raw->id);
 		blk->name = raw->name;
-		blk->name_len = strlen(raw->name);
+		blk->name_len = strnlen(raw->name, ARRAY_SIZE(raw->name));
 		blk->ncoeff = le32_to_cpu(raw->ncoeff);
@@ -1260,4 +1260,4 @@ static int cs_dsp_coeff_parse_coeff(struct cs_dsp *dsp,
 		blk->name = raw->name;
-		blk->name_len = strlen(raw->name);
+		blk->name_len = strnlen(raw->name, ARRAY_SIZE(raw->name));
 		blk->ctl_type = le16_to_cpu(raw->ctl_type);
 		blk->flags = le16_to_cpu(raw->flags);
-- 
2.39.2

On 08/07/2024 16:20, Richard Fitzgerald wrote:
> Use strnlen() instead of strlen() on the algorithm and coefficient name
> string arrays in V1 wmfw files.
> 
> In V1 wmfw files the name is a NUL-terminated string in a fixed-size
> array. cs_dsp should protect against overrunning the array if the NUL
> terminator is missing.
> 
> Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
> Fixes: f6bc909e7673 ("firmware: cs_dsp: add driver to support firmware loading on Cirrus Logic DSPs")
> ---
>   drivers/firmware/cirrus/cs_dsp.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c
> index 16484ab9b09d..8a347b938406 100644
> --- a/drivers/firmware/cirrus/cs_dsp.c
> +++ b/drivers/firmware/cirrus/cs_dsp.c
> @@ -1183,4 +1183,4 @@ static int cs_dsp_coeff_parse_alg(struct cs_dsp *dsp,
>   		blk->id = le32_to_cpu(raw->id);
>   		blk->name = raw->name;
> -		blk->name_len = strlen(raw->name);
> +		blk->name_len = strnlen(raw->name, ARRAY_SIZE(raw->name));
>   		blk->ncoeff = le32_to_cpu(raw->ncoeff);
> @@ -1260,4 +1260,4 @@ static int cs_dsp_coeff_parse_coeff(struct cs_dsp *dsp,
>   		blk->name = raw->name;
> -		blk->name_len = strlen(raw->name);
> +		blk->name_len = strnlen(raw->name, ARRAY_SIZE(raw->name));
>   		blk->ctl_type = le16_to_cpu(raw->ctl_type);
>   		blk->flags = le16_to_cpu(raw->flags);

This is the same patch as V1 but with a couple of conflicting
lines dropped from the context. You can ignore this V2 if you've got
V1 to apply cleanly.

Sorry for the confusion.