diff mbox series

[01/11] staging: vc04_services: changen strncpy() to strscpy_pad()

Message ID 20240328140512.4148825-2-arnd@kernel.org (mailing list archive)
State New, archived
Headers show
Series address remaining stringop-truncation warnings | expand

Commit Message

Arnd Bergmann March 28, 2024, 2:04 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

gcc-14 warns about this strncpy() that results in a non-terminated
string for an overflow:

In file included from include/linux/string.h:369,
                 from drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:20:
In function 'strncpy',
    inlined from 'create_component' at drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:940:2:
include/linux/fortify-string.h:108:33: error: '__builtin_strncpy' specified bound 128 equals destination size [-Werror=stringop-truncation]

Change it to strscpy_pad(), which produces a properly terminated and
zero-padded string.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Dan Carpenter March 28, 2024, 2:42 p.m. UTC | #1 
On Thu, Mar 28, 2024 at 03:04:45PM +0100, Arnd Bergmann wrote:
> diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> index 258aa0e37f55..6ca5797aeae5 100644
> --- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> +++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> @@ -937,8 +937,8 @@ static int create_component(struct vchiq_mmal_instance *instance,
>  	/* build component create message */
>  	m.h.type = MMAL_MSG_TYPE_COMPONENT_CREATE;
>  	m.u.component_create.client_component = component->client_component;
> -	strncpy(m.u.component_create.name, name,
> -		sizeof(m.u.component_create.name));
> +	strscpy_pad(m.u.component_create.name, name,
> +		    sizeof(m.u.component_create.name));

You sent this earlier and we already applied it.

Btw, I just learned there is a new trick to write this when it's just
sizeof(dest).

	strscpy_pad(m.u.component_create.name, name);

regards,
dan carpenter
Arnd Bergmann March 28, 2024, 4:15 p.m. UTC | #2 
On Thu, Mar 28, 2024, at 15:42, Dan Carpenter wrote:
> On Thu, Mar 28, 2024 at 03:04:45PM +0100, Arnd Bergmann wrote:
>> diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
>> index 258aa0e37f55..6ca5797aeae5 100644
>> --- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
>> +++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
>> @@ -937,8 +937,8 @@ static int create_component(struct vchiq_mmal_instance *instance,
>>  	/* build component create message */
>>  	m.h.type = MMAL_MSG_TYPE_COMPONENT_CREATE;
>>  	m.u.component_create.client_component = component->client_component;
>> -	strncpy(m.u.component_create.name, name,
>> -		sizeof(m.u.component_create.name));
>> +	strscpy_pad(m.u.component_create.name, name,
>> +		    sizeof(m.u.component_create.name));
>
> You sent this earlier and we already applied it.

Sorry about that. I normally mark patches I send as applied
in the subject but it looks like I lost the annotation
by accident.

> Btw, I just learned there is a new trick to write this when it's just
> sizeof(dest).
>
> 	strscpy_pad(m.u.component_create.name, name);

Ah, cute.

     arnd
Justin Stitt March 28, 2024, 11:10 p.m. UTC | #3 
Hi,

On Thu, Mar 28, 2024 at 03:04:45PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> gcc-14 warns about this strncpy() that results in a non-terminated
> string for an overflow:
> 
> In file included from include/linux/string.h:369,
>                  from drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:20:
> In function 'strncpy',
>     inlined from 'create_component' at drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c:940:2:
> include/linux/fortify-string.h:108:33: error: '__builtin_strncpy' specified bound 128 equals destination size [-Werror=stringop-truncation]
> 
> Change it to strscpy_pad(), which produces a properly terminated and
> zero-padded string.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

If there is other review that warrants a change, we might as well switch
over to the new 2-argument version of strscpy{_pad}() introduced in
Commit e6584c3964f2f ("string: Allow 2-argument strscpy()"). No need to
change for only this reason, though.

Reviewed-by: Justin Stitt <justinstitt@google.com>

> ---
>  drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> index 258aa0e37f55..6ca5797aeae5 100644
> --- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> +++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
> @@ -937,8 +937,8 @@ static int create_component(struct vchiq_mmal_instance *instance,
>  	/* build component create message */
>  	m.h.type = MMAL_MSG_TYPE_COMPONENT_CREATE;
>  	m.u.component_create.client_component = component->client_component;
> -	strncpy(m.u.component_create.name, name,
> -		sizeof(m.u.component_create.name));
> +	strscpy_pad(m.u.component_create.name, name,
> +		    sizeof(m.u.component_create.name));
>  
>  	ret = send_synchronous_mmal_msg(instance, &m,
>  					sizeof(m.u.component_create),
> -- 
> 2.39.2
> 

Thanks
Justin
diff mbox series

Patch

diff --git a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
index 258aa0e37f55..6ca5797aeae5 100644
--- a/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
+++ b/drivers/staging/vc04_services/vchiq-mmal/mmal-vchiq.c
@@ -937,8 +937,8 @@  static int create_component(struct vchiq_mmal_instance *instance,
 	/* build component create message */
 	m.h.type = MMAL_MSG_TYPE_COMPONENT_CREATE;
 	m.u.component_create.client_component = component->client_component;
-	strncpy(m.u.component_create.name, name,
-		sizeof(m.u.component_create.name));
+	strscpy_pad(m.u.component_create.name, name,
+		    sizeof(m.u.component_create.name));
 
 	ret = send_synchronous_mmal_msg(instance, &m,
 					sizeof(m.u.component_create),