From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, PaX Team , Mathias Krause , David Rientjes , Suresh Siddha , Ingo Molnar Subject: [ 22/77] x86/apic: Fix parsing of the lapic cmdline option Date: Fri, 1 Mar 2013 11:44:07 -0800 Message-Id: <20130301194354.354775176@linuxfoundation.org> In-Reply-To: <20130301194351.913471337@linuxfoundation.org> References: <20130301194351.913471337@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Krause commit 27cf929845b10043f2257693c7d179a9e0b1980e upstream. Including " lapic " in the kernel cmdline on an x86-64 kernel makes it panic while parsing early params -- e.g. with no user visible output. Fix this bug by ensuring arg is non-NULL before passing it to strncmp(). Reported-by: PaX Team Signed-off-by: Mathias Krause Acked-by: David Rientjes Cc: Suresh Siddha Link: http://lkml.kernel.org/r/1361303227-13174-1-git-send-email-minipli@googlemail.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/apic/apic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -131,7 +131,7 @@ static int __init parse_lapic(char *arg) { if (config_enabled(CONFIG_X86_32) && !arg) force_enable_local_apic = 1; - else if (!strncmp(arg, "notscdeadline", 13)) + else if (arg && !strncmp(arg, "notscdeadline", 13)) setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER); return 0; }