console: Fix console name size mismatch

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.

Cc: <stable@vger.kernel.org> # 2.6.22+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 2 insertions, 1 deletions

diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h
index cbd69d842341..2ca4a8b5fe57 100644
--- a/kernel/printk/console_cmdline.h
+++ b/kernel/printk/console_cmdline.h
@@ -3,7 +3,7 @@
 
 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
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 01cfd69c54c6..bb0635bd74f2 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2464,6 +2464,7 @@ void register_console(struct console *newcon)
         for (i = 0, c = console_cmdline;
              i < MAX_CMDLINECONSOLES && c->name[0];
              i++, c++) {
+                BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
                 if (strcmp(c->name, newcon->name) != 0)
                         continue;
                 if (newcon->index >= 0 &&