From 8c5eb85136fd2482c5be3c2d249351eae219cca5 Mon Sep 17 00:00:00 2001
From: "Vanya A. Sergeev" <v@sergeev.io>
Date: Fri, 10 Oct 2025 23:29:50 -0500
Subject: [PATCH] led: fix null termination of internal buffers

unlikely to be encountered, but handled correctly now.
---
 src/led.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/led.c b/src/led.c
index 53d2261..a9e6cd8 100644
--- a/src/led.c
+++ b/src/led.c
@@ -111,18 +111,17 @@ int led_get_brightness(led_t *led, unsigned int *brightness) {
     if ((fd = open(led_path, O_RDONLY)) < 0)
         return _led_error(led, LED_ERROR_IO, errno, "Opening LED 'brightness'");
 
-    if ((ret = read(fd, buf, sizeof(buf))) < 0) {
+    if ((ret = read(fd, buf, sizeof(buf) - 1)) < 0) {
         int errsv = errno;
         close(fd);
         return _led_error(led, LED_ERROR_IO, errsv, "Reading LED 'brightness'");
     }
 
+    buf[ret] = '\0';
+
     if (close(fd) < 0)
         return _led_error(led, LED_ERROR_IO, errno, "Closing LED 'brightness'");
 
-    /* Null-terminate over newline */
-    buf[ret] = '\0';
-
     *brightness = strtoul(buf, NULL, 10);
 
     return 0;
@@ -138,18 +137,17 @@ int led_get_max_brightness(led_t *led, unsigned int *max_brightness) {
     if ((fd = open(led_path, O_RDONLY)) < 0)
         return _led_error(led, LED_ERROR_QUERY, errno, "Opening LED 'max_brightness'");
 
-    if ((ret = read(fd, buf, sizeof(buf))) < 0) {
+    if ((ret = read(fd, buf, sizeof(buf) - 1)) < 0) {
         int errsv = errno;
         close(fd);
         return _led_error(led, LED_ERROR_QUERY, errsv, "Reading LED 'max_brightness'");
     }
 
+    buf[ret] = '\0';
+
     if (close(fd) < 0)
         return _led_error(led, LED_ERROR_QUERY, errno, "Closing LED 'max_brightness'");
 
-    /* Null-terminate over newline */
-    buf[ret] = '\0';
-
     led->max_brightness = strtoul(buf, NULL, 10);
 
     *max_brightness = led->max_brightness;