Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755388AbbLJSkb (ORCPT ); Thu, 10 Dec 2015 13:40:31 -0500 Received: from terminus.zytor.com ([198.137.202.10]:34115 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751268AbbLJSk1 (ORCPT ); Thu, 10 Dec 2015 13:40:27 -0500 Date: Thu, 10 Dec 2015 10:40:15 -0800 From: tip-bot for Jiang Liu Message-ID: Cc: joe.lawrence@stratus.com, jiang.liu@linux.intel.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, mingo@kernel.org Reply-To: joe.lawrence@stratus.com, jiang.liu@linux.intel.com, mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, tglx@linutronix.de In-Reply-To: <1448870970-1461-3-git-send-email-jiang.liu@linux.intel.com> References: <1448870970-1461-3-git-send-email-jiang.liu@linux.intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/urgent] x86/irq: Fix a race window in x86_vector_free_irqs() Git-Commit-ID: 21a1b3bf35018b446c943c15f0a6225e6f6497ae X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3642 Lines: 104 Commit-ID: 21a1b3bf35018b446c943c15f0a6225e6f6497ae Gitweb: http://git.kernel.org/tip/21a1b3bf35018b446c943c15f0a6225e6f6497ae Author: Jiang Liu AuthorDate: Mon, 30 Nov 2015 16:09:28 +0800 Committer: Thomas Gleixner CommitDate: Thu, 10 Dec 2015 19:32:07 +0100 x86/irq: Fix a race window in x86_vector_free_irqs() There's a race condition between x86_vector_free_irqs() { free_apic_chip_data(irq_data->chip_data); xxxxx //irq_data->chip_data has been freed, but the pointer //hasn't been reset yet irq_domain_reset_irq_data(irq_data); } and smp_irq_move_cleanup_interrupt() { raw_spin_lock(&vector_lock); data = apic_chip_data(irq_desc_get_irq_data(desc)); access data->xxxx // may access freed memory raw_spin_unlock(&desc->lock); } , which may cause smp_irq_move_cleanup_interrupt() accesses freed memory. So use vector_lock to guard all memory free code in x86_vector_free_irqs(). Fixes: a782a7e46bb5 "x86/irq: Store irq descriptor in vector array" Reported-and-tested-by: Joe Lawrence Signed-off-by: Jiang Liu Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1448870970-1461-3-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/vector.c | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c index f03957e..57934ef 100644 --- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -231,23 +231,16 @@ static int assign_irq_vector_policy(int irq, int node, static void clear_irq_vector(int irq, struct apic_chip_data *data) { struct irq_desc *desc; - unsigned long flags; - int cpu, vector; - - raw_spin_lock_irqsave(&vector_lock, flags); - BUG_ON(!data->cfg.vector); + int cpu, vector = data->cfg.vector; - vector = data->cfg.vector; + BUG_ON(!vector); for_each_cpu_and(cpu, data->domain, cpu_online_mask) per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED; - data->cfg.vector = 0; cpumask_clear(data->domain); - if (likely(!data->move_in_progress)) { - raw_spin_unlock_irqrestore(&vector_lock, flags); + if (likely(!data->move_in_progress)) return; - } desc = irq_to_desc(irq); for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) { @@ -260,7 +253,7 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data) } } data->move_in_progress = 0; - raw_spin_unlock_irqrestore(&vector_lock, flags); + cpumask_clear(data->old_domain); } void init_irq_alloc_info(struct irq_alloc_info *info, @@ -282,18 +275,21 @@ static void x86_vector_free_irqs(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs) { struct irq_data *irq_data; + unsigned long flags; int i; for (i = 0; i < nr_irqs; i++) { irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i); if (irq_data && irq_data->chip_data) { + raw_spin_lock_irqsave(&vector_lock, flags); clear_irq_vector(virq + i, irq_data->chip_data); free_apic_chip_data(irq_data->chip_data); + irq_domain_reset_irq_data(irq_data); + raw_spin_unlock_irqrestore(&vector_lock, flags); #ifdef CONFIG_X86_IO_APIC if (virq + i < nr_legacy_irqs()) legacy_irq_data[virq + i] = NULL; #endif - irq_domain_reset_irq_data(irq_data); } } } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/