[v2,4/4] soc: apple: rtkit: Cut syslog messages after the first '\0'

Commit Message

Sven Peter via B4 Relay Feb. 26, 2025, 7 p.m. UTC

From: Janne Grunau <[e-mail]>

Certain messages from DCP contain NUL bytes in the random data after the
NUL terminated syslog message. Since the syslog message ends with '\n'
this results in a dev_info() message terminated with two newlines and an
empty printed line in the kernel log.

Signed-off-by: Janne Grunau <[e-mail]>
Reviewed-by: Alyssa Rosenzweig <[e-mail]>
Signed-off-by: Sven Peter <[e-mail]>
---
 drivers/soc/apple/rtkit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/drivers/soc/apple/rtkit.c b/drivers/soc/apple/rtkit.c
index 4b78463dd5a1..5fffd0f003dc 100644
--- a/drivers/soc/apple/rtkit.c
+++ b/drivers/soc/apple/rtkit.c
@@ -477,7 +477,7 @@  static void apple_rtkit_syslog_rx_log(struct apple_rtkit *rtk, u64 msg)
 
 	log_context[sizeof(log_context) - 1] = 0;
 
-	msglen = rtk->syslog_msg_size - 1;
+	msglen = strnlen(rtk->syslog_msg_buffer, rtk->syslog_msg_size - 1);
 	while (msglen > 0 &&
 		   should_crop_syslog_char(rtk->syslog_msg_buffer[msglen - 1]))
 		msglen--;