[PATCH] staging: vc04_services: changen strncpy() to strscpy_pad()

[PATCH] staging: vc04_services: changen strncpy() to strscpy_pad()

[Arnd Bergmann]

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(-)

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


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Re: [PATCH] staging: vc04_services: changen strncpy() to strscpy_pad()

[Dan Carpenter]

On Wed, Mar 13, 2024 at 05:36:56PM +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>
> ---

Thanks, Arnd!

Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>

(Greg is on vacation so I'm playing Greg for two weeks).

In real life, 128 is way larger than necessary so it's not an issue,
which is presumably why you left off the Fixes tag.  Anyway, it's always
good to replace another strncpy().

I see another bug here where m.u.component_create.pid is never
initialized.  I'll send a "m.u.component_create.pid = 0;" fix for that
based on top of your patch.

regards,
dan carpenter


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