From: Jason Wessel <jason.wessel@windriver.com>
Date: Fri, 26 Sep 2008 15:36:42 +0000 (-0500)
Subject: kgdboc,tty: Fix tty polling search to use name correctly
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0dca0fd2bfeb99738708d6c9117994ebf398e72c;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

kgdboc,tty: Fix tty polling search to use name correctly

The tty_find_polling_driver() routine did not correctly check the base
part of the tty name.  This can lead to kgdboc selecting an incorrect
driver, as well as accepting a completely invalid tty such as "echo
ffff0 > /sys/module/kgdboc/parameters/kgdboc".

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index daeb8f76697..e4dce870954 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -695,13 +695,23 @@ struct tty_driver *tty_find_polling_driver(char *name, int *line)
 {
 	struct tty_driver *p, *res = NULL;
 	int tty_line = 0;
+	int len;
 	char *str;
 
+	for (str = name; *str; str++)
+		if ((*str >= '0' && *str <= '9') || *str == ',')
+			break;
+	if (!*str)
+		return NULL;
+
+	len = str - name;
+	tty_line = simple_strtoul(str, &str, 10);
+
 	mutex_lock(&tty_mutex);
 	/* Search through the tty devices to look for a match */
 	list_for_each_entry(p, &tty_drivers, tty_drivers) {
-		str = name + strlen(p->name);
-		tty_line = simple_strtoul(str, &str, 10);
+		if (strncmp(name, p->name, len) != 0)
+			continue;
 		if (*str == ',')
 			str++;
 		if (*str == '\0')