| Message ID | 20170419171543.3274995-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 19/04/17 19:15, Arnd Bergmann wrote: > gcc warns about an obviously incorrect use of strncat(): > > drivers/media/usb/rainshadow-cec/rainshadow-cec.c: In function 'rain_cec_adap_transmit': > drivers/media/usb/rainshadow-cec/rainshadow-cec.c:299:4: error: specified bound 48 equals the size of the destination [-Werror=stringop-overflow=] > > It seems that strlcat was intended here, and using that makes the > code correct. Oops! You're right, it should be strlcat. Which gcc version do you use? Mine (6.3.0) didn't give an error (or warning, for that matter). Regards, Hans > > Fixes: 0f314f6c2e77 ("[media] rainshadow-cec: new RainShadow Tech HDMI CEC driver") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > drivers/media/usb/rainshadow-cec/rainshadow-cec.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c > index 541ca543f71f..dc1f64f904cd 100644 > --- a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c > +++ b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c > @@ -296,7 +296,7 @@ static int rain_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, > cec_msg_destination(msg), msg->msg[1]); > for (i = 2; i < msg->len; i++) { > snprintf(hex, sizeof(hex), "%02x", msg->msg[i]); > - strncat(cmd, hex, sizeof(cmd)); > + strlcat(cmd, hex, sizeof(cmd)); > } > } > mutex_lock(&rain->write_lock); >
On Wed, Apr 19, 2017 at 11:14 PM, Hans Verkuil <hverkuil@xs4all.nl> wrote: > On 19/04/17 19:15, Arnd Bergmann wrote: >> gcc warns about an obviously incorrect use of strncat(): >> >> drivers/media/usb/rainshadow-cec/rainshadow-cec.c: In function 'rain_cec_adap_transmit': >> drivers/media/usb/rainshadow-cec/rainshadow-cec.c:299:4: error: specified bound 48 equals the size of the destination [-Werror=stringop-overflow=] >> >> It seems that strlcat was intended here, and using that makes the >> code correct. > > Oops! You're right, it should be strlcat. > > Which gcc version do you use? Mine (6.3.0) didn't give an error (or warning, for that matter). I think the warning was only added in gcc-7.0.1. Arnd
diff --git a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c index 541ca543f71f..dc1f64f904cd 100644 --- a/drivers/media/usb/rainshadow-cec/rainshadow-cec.c +++ b/drivers/media/usb/rainshadow-cec/rainshadow-cec.c @@ -296,7 +296,7 @@ static int rain_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, cec_msg_destination(msg), msg->msg[1]); for (i = 2; i < msg->len; i++) { snprintf(hex, sizeof(hex), "%02x", msg->msg[i]); - strncat(cmd, hex, sizeof(cmd)); + strlcat(cmd, hex, sizeof(cmd)); } } mutex_lock(&rain->write_lock);
gcc warns about an obviously incorrect use of strncat(): drivers/media/usb/rainshadow-cec/rainshadow-cec.c: In function 'rain_cec_adap_transmit': drivers/media/usb/rainshadow-cec/rainshadow-cec.c:299:4: error: specified bound 48 equals the size of the destination [-Werror=stringop-overflow=] It seems that strlcat was intended here, and using that makes the code correct. Fixes: 0f314f6c2e77 ("[media] rainshadow-cec: new RainShadow Tech HDMI CEC driver") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- drivers/media/usb/rainshadow-cec/rainshadow-cec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)