[PATCH] tools: gpio: fix buffer overflow and add bounds check

From: Zhang Xiaolei

Date: Sun May 03 2026 - 15:00:31 EST


Replace strcpy() with strncpy() to avoid potential buffer overflow
in req.consumer. Also add validation for num_lines to prevent
out-of-bounds access to req.offsets.

Fix incorrect ioctl name in error message.

Signed-off-by: Zhang Xiaolei <zxl434815272@xxxxxxxxx>
---
tools/gpio/gpio-utils.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tools/gpio/gpio-utils.c b/tools/gpio/gpio-utils.c
index 4096bcd511d1..1afd9dff2bed 100644
--- a/tools/gpio/gpio-utils.c
+++ b/tools/gpio/gpio-utils.c
@@ -65,11 +65,15 @@ int gpiotools_request_line(const char *device_name, unsigned int *lines,
int i;
int ret;

+ if (!device_name || !lines || !config || !consumer ||
+ num_lines == 0 || num_lines > GPIO_V2_LINES_MAX)
+ return -EINVAL;
+
ret = asprintf(&chrdev_name, "/dev/%s", device_name);
if (ret < 0)
return -ENOMEM;

- fd = open(chrdev_name, 0);
+ fd = open(chrdev_name, O_RDONLY);
if (fd == -1) {
ret = -errno;
fprintf(stderr, "Failed to open %s, %s\n",
@@ -78,27 +82,29 @@ int gpiotools_request_line(const char *device_name, unsigned int *lines,
}

memset(&req, 0, sizeof(req));
+
for (i = 0; i < num_lines; i++)
req.offsets[i] = lines[i];

req.config = *config;
- strcpy(req.consumer, consumer);
+ strncpy(req.consumer, consumer, sizeof(req.consumer) - 1);
+ req.consumer[sizeof(req.consumer) - 1] = '\0';
req.num_lines = num_lines;

ret = ioctl(fd, GPIO_V2_GET_LINE_IOCTL, &req);
if (ret == -1) {
ret = -errno;
fprintf(stderr, "Failed to issue %s (%d), %s\n",
- "GPIO_GET_LINE_IOCTL", ret, strerror(errno));
+ "GPIO_V2_GET_LINE_IOCTL", ret, strerror(errno));
}

if (close(fd) == -1)
perror("Failed to close GPIO character device file");
+
exit_free_name:
free(chrdev_name);
return ret < 0 ? ret : req.fd;
}
-
/**
* gpiotools_set_values() - Set the value of gpio(s)
* @fd: The fd returned by
--
2.54.0