Messages in this thread Patches in this message | | | Date | Mon, 9 Jan 2023 14:36:00 +0100 | Subject | Re: [PATCH linux-next] ALSA: control-led: use strscpy() to instead of strncpy() | From | Jaroslav Kysela <> |
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On 09. 01. 23 13:40, Takashi Iwai wrote: > On Mon, 09 Jan 2023 12:45:51 +0100, > <yang.yang29@zte.com.cn> wrote: >> >> From: Xu Panda <xu.panda@zte.com.cn> >> >> The implementation of strscpy() is more robust and safer. >> That's now the recommended way to copy NUL-terminated strings. >> >> Signed-off-by: Xu Panda <xu.panda@zte.com.cn> >> Signed-off-by: Yang Yang <yang.yang29@zte.com.cn> >> --- >> sound/core/control_led.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/sound/core/control_led.c b/sound/core/control_led.c >> index f975cc85772b..c88653c205eb 100644 >> --- a/sound/core/control_led.c >> +++ b/sound/core/control_led.c >> @@ -534,8 +534,7 @@ static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, si >> struct snd_ctl_elem_id id; >> int err; >> >> - strncpy(buf2, buf, len); >> - buf2[len] = '\0'; >> + strncpy(buf2, buf, len + 1); > > Still using strncpy()...?
The original code should be:
diff --git a/sound/core/control_led.c b/sound/core/control_led.c index f975cc85772b..b44abefcb593 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -530,7 +530,7 @@ static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, si bool attach) { char buf2[256], *s, *os; - size_t len = max(sizeof(s) - 1, count); + size_t len = min(sizeof(buf2) - 1, count); struct snd_ctl_elem_id id; int err;
But it can be replaced with: diff --git a/sound/core/control_led.c b/sound/core/control_led.c index f975cc85772b..41d4e898d34c 100644 --- a/sound/core/control_led.c +++ b/sound/core/control_led.c @@ -530,12 +530,11 @@ static ssize_t set_led_id(struct snd_ctl_led_card *led_card, const char *buf, si bool attach) { char buf2[256], *s, *os; - size_t len = max(sizeof(s) - 1, count); struct snd_ctl_elem_id id; int err;
- strncpy(buf2, buf, len); - buf2[len] = '\0'; + if (strscpy(buf2, buf, count) < 0) + return -E2BIG; memset(&id, 0, sizeof(id)); id.iface = SNDRV_CTL_ELEM_IFACE_MIXER; s = buf2; I'll send a patch ASAP.
Jaroslav
-- Jaroslav Kysela <perex@perex.cz> Linux Sound Maintainer; ALSA Project; Red Hat, Inc.
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