[PATCH 3.2 090/221] console: Fix console name size mismatch

Ben Hutchings
2015-05-05T01:37:21Z

From: Peter Hurley <peter@hurleysoftware.com>

commit 30a22c215a0007603ffc08021f2e8b64018517dd upstream.

commit 6ae9200f2cab7 ("enlarge console.name") increased the storage
for the console name to 16 bytes, but not the corresponding
struct console_cmdline::name storage. Console names longer than
8 bytes cause read beyond end-of-string and failure to match
console; I'm not sure if there are other unexpected consequences.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
- Adjust filename
- Use console_cmdline[i] instead of *c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -123,7 +123,7 @@ static struct console *exclusive_console
*/
struct console_cmdline
{
- char name[8]; /* Name of the driver */
+ char name[16]; /* Name of the driver */
int index; /* Minor dev. to use */
char *options; /* Options for the driver */
#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
@@ -1477,6 +1477,7 @@ void register_console(struct console *ne
*/
for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
i++) {
+ BUILD_BUG_ON(sizeof(console_cmdline[i].name) != sizeof(newcon->name));
if (strcmp(console_cmdline[i].name, newcon->name) != 0)
continue;
if (newcon->index >= 0 &&