From: Benjamin Herrenschmidt Date: Wed, 23 Nov 2005 21:37:44 +0000 (-0800) Subject: [PATCH] Fix crash in unregister_console() X-Git-Tag: v2.6.15-rc4~48 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=e9b15b54d3646108bbd3e054158b402025d3e704;p=~emulex%2Finfiniband.git [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/printk.c b/kernel/printk.c index ac8a08f3620..5287be83e3e 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -956,7 +956,7 @@ int unregister_console(struct console *console) 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) {