diff mbox series

ALSA: xen: ensure nul-terminated device name

Message ID 20180528160011.2989632-1-arnd@arndb.de
State Accepted
Commit 4c0eaac716d8e461584a4c8529cb00c72a563fa8
Headers show
Series ALSA: xen: ensure nul-terminated device name | expand

Commit Message

Arnd Bergmann May 28, 2018, 3:59 p.m. UTC
gcc-8 warns that pcm_instance->name is not necessarily terminated correctly
if the input is more than 80 characters long or lacks a termination byte
itself:

In function 'strncpy',
    inlined from 'cfg_device' at sound/xen/xen_snd_front_cfg.c:399:3,
    inlined from 'xen_snd_front_cfg_card' at sound/xen/xen_snd_front_cfg.c:509:9:
include/linux/string.h:254:9: error: '__builtin_strncpy' specified bound 80 equals destination size [-Werror=stringop-truncation]
  return __builtin_strncpy(p, q, size);

Using strlcpy() instead of strncpy() makes this a bit safer.

Fixes: fd3b36045c2c ("ALSA: xen-front: Read sound driver configuration from Xen store")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 sound/xen/xen_snd_front_cfg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

-- 
2.9.0

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Comments

Oleksandr Andrushchenko May 29, 2018, 5:48 a.m. UTC | #1
On 05/28/2018 06:59 PM, Arnd Bergmann wrote:
> gcc-8 warns that pcm_instance->name is not necessarily terminated correctly

> if the input is more than 80 characters long or lacks a termination byte

> itself:

>

> In function 'strncpy',

>      inlined from 'cfg_device' at sound/xen/xen_snd_front_cfg.c:399:3,

>      inlined from 'xen_snd_front_cfg_card' at sound/xen/xen_snd_front_cfg.c:509:9:

> include/linux/string.h:254:9: error: '__builtin_strncpy' specified bound 80 equals destination size [-Werror=stringop-truncation]

>    return __builtin_strncpy(p, q, size);

>

> Using strlcpy() instead of strncpy() makes this a bit safer.

>

> Fixes: fd3b36045c2c ("ALSA: xen-front: Read sound driver configuration from Xen store")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> ---

>   sound/xen/xen_snd_front_cfg.c | 2 +-

>   1 file changed, 1 insertion(+), 1 deletion(-)

>

> diff --git a/sound/xen/xen_snd_front_cfg.c b/sound/xen/xen_snd_front_cfg.c

> index 38c7e1eefbb9..684b5f1d51ac 100644

> --- a/sound/xen/xen_snd_front_cfg.c

> +++ b/sound/xen/xen_snd_front_cfg.c

> @@ -396,7 +396,7 @@ static int cfg_device(struct xen_snd_front_info *front_info,

>   

>   	str = xenbus_read(XBT_NIL, device_path, XENSND_FIELD_DEVICE_NAME, NULL);

>   	if (!IS_ERR(str)) {

> -		strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));

> +		strlcpy(pcm_instance->name, str, sizeof(pcm_instance->name));

>   		kfree(str);

>   	}

>   

Thank you for your patch,
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>

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Takashi Iwai May 29, 2018, 6:28 a.m. UTC | #2
On Tue, 29 May 2018 07:48:51 +0200,
Oleksandr Andrushchenko wrote:
> 

> On 05/28/2018 06:59 PM, Arnd Bergmann wrote:

> > gcc-8 warns that pcm_instance->name is not necessarily terminated correctly

> > if the input is more than 80 characters long or lacks a termination byte

> > itself:

> >

> > In function 'strncpy',

> >      inlined from 'cfg_device' at sound/xen/xen_snd_front_cfg.c:399:3,

> >      inlined from 'xen_snd_front_cfg_card' at sound/xen/xen_snd_front_cfg.c:509:9:

> > include/linux/string.h:254:9: error: '__builtin_strncpy' specified bound 80 equals destination size [-Werror=stringop-truncation]

> >    return __builtin_strncpy(p, q, size);

> >

> > Using strlcpy() instead of strncpy() makes this a bit safer.

> >

> > Fixes: fd3b36045c2c ("ALSA: xen-front: Read sound driver configuration from Xen store")

> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

> > ---

> >   sound/xen/xen_snd_front_cfg.c | 2 +-

> >   1 file changed, 1 insertion(+), 1 deletion(-)

> >

> > diff --git a/sound/xen/xen_snd_front_cfg.c b/sound/xen/xen_snd_front_cfg.c

> > index 38c7e1eefbb9..684b5f1d51ac 100644

> > --- a/sound/xen/xen_snd_front_cfg.c

> > +++ b/sound/xen/xen_snd_front_cfg.c

> > @@ -396,7 +396,7 @@ static int cfg_device(struct xen_snd_front_info *front_info,

> >     	str = xenbus_read(XBT_NIL, device_path,

> > XENSND_FIELD_DEVICE_NAME, NULL);

> >   	if (!IS_ERR(str)) {

> > -		strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));

> > +		strlcpy(pcm_instance->name, str, sizeof(pcm_instance->name));

> >   		kfree(str);

> >   	}

> >   

> Thank you for your patch,

> Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>


Applied now.  Thanks.


Takashi
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diff mbox series

Patch

diff --git a/sound/xen/xen_snd_front_cfg.c b/sound/xen/xen_snd_front_cfg.c
index 38c7e1eefbb9..684b5f1d51ac 100644
--- a/sound/xen/xen_snd_front_cfg.c
+++ b/sound/xen/xen_snd_front_cfg.c
@@ -396,7 +396,7 @@  static int cfg_device(struct xen_snd_front_info *front_info,
 
 	str = xenbus_read(XBT_NIL, device_path, XENSND_FIELD_DEVICE_NAME, NULL);
 	if (!IS_ERR(str)) {
-		strncpy(pcm_instance->name, str, sizeof(pcm_instance->name));
+		strlcpy(pcm_instance->name, str, sizeof(pcm_instance->name));
 		kfree(str);
 	}