[PATCH 01/28] ALSA: ac97: Refactor snd_ac97_get_name() to use snprintf()

snd_ac97_get_name() appends the codec name using two strlcat() calls and
then appends the revision using an unbounded sprintf() at
"name + strlen(name)", which could overflow the destination buffer.

In preparation for removing the deprecated strlcat() API[1], replace the
strlcat() and sprintf() calls with a single snprintf() using the existing
string length, matching the pattern already used in the "else" branch.

Link: https://github.com/KSPP/linux/issues/370 [1]
Cc: codemender-patching+linux@google.com
Assisted-by: Claude-3-5-Sonnet:20241022 [editor_update_file, shell_command_run]
Signed-off-by: Bill Wendling <morbo@google.com>
---
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---
 sound/pci/ac97/ac97_codec.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/sound/pci/ac97/ac97_codec.c b/sound/pci/ac97/ac97_codec.c
index 0bb65be021d9..e145099ee02a 100644
--- a/sound/pci/ac97/ac97_codec.c
+++ b/sound/pci/ac97/ac97_codec.c

@@ -1850,10 +1850,12 @@ void snd_ac97_get_name(struct snd_ac97 *ac97, unsigned int id, char *name,
 
 	pid = look_for_codec_id(snd_ac97_codec_ids, id);
 	if (pid) {
-		strlcat(name, " ", maxlen);
-		strlcat(name, pid->name, maxlen);
+		int l = strlen(name);
+
 		if (pid->mask != 0xffffffff)
-			sprintf(name + strlen(name), " rev %u", id & ~pid->mask);
+			snprintf(name + l, maxlen - l, " %s rev %u", pid->name, id & ~pid->mask);
+		else
+			snprintf(name + l, maxlen - l, " %s", pid->name);
 		if (ac97 && pid->patch) {
 			if ((modem && (pid->flags & AC97_MODEM_PATCH)) ||
 			    (! modem && ! (pid->flags & AC97_MODEM_PATCH)))

@@ -1861,6 +1863,7 @@ void snd_ac97_get_name(struct snd_ac97 *ac97, unsigned int id, char *name,
 		}
 	} else {
 		int l = strlen(name);
+
 		snprintf(name + l, maxlen - l, " id %x", id & 0xff);
 	}
 }

-- 
2.55.0.1032.g73a4cd73de-goog