[PATCH] Fix crash in unregister_console()
If unregister_console() is inadvertently called while no consoles are
registered, it will crash trying to dereference NULL pointer. It is
necessary to fix that because register_console() provides no indication
that it actually registered the console passed in. In fact, it may well
decide not to register it based on various things...
(akpm: It'd be better to make register_console() return something and fix the
callers. All 106 of them...)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/printk.c b/kernel/printk.c
index ac8a08f..5287be8 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -956,7 +956,7 @@
if (console_drivers == console) {
console_drivers=console->next;
res = 0;
- } else {
+ } else if (console_drivers) {
for (a=console_drivers->next, b=console_drivers ;
a; b=a, a=b->next) {
if (a == console) {
