[Security] bug in led_proc_write()

Commit Message

Helge Deller Aug. 2, 2010, 8:46 p.m. UTC

None

Patch

diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index 188bc84..d02be78 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -176,16 +176,18 @@  static ssize_t led_proc_write(struct file *file, const char *buf,
 	size_t count, loff_t *pos)
 {
 	void *data = PDE(file->f_path.dentry->d_inode)->data;
-	char *cur, lbuf[count + 1];
+	char *cur, lbuf[32];
 	int d;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 
-	memset(lbuf, 0, count + 1);
+	if (count >= sizeof(lbuf))
+		count = sizeof(lbuf)-1;
 
 	if (copy_from_user(lbuf, buf, count))
 		return -EFAULT;
+	lbuf[count] = 0;
 
 	cur = lbuf;