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authorJiang Liu <jiang.liu@linux.intel.com>2015-12-31 16:30:44 +0000
committerThomas Gleixner <tglx@linutronix.de>2016-01-15 13:43:58 +0100
commit111abeba67e0dbdc26537429de9155e4f1d807d8 (patch)
treee286d31b727f6f13d12ea3c7625f8adde1e06fbb /arch/x86
parente23b257c293ce4bcc8cabb2aa3097b6ed8a8261a (diff)
downloadop-kernel-dev-111abeba67e0dbdc26537429de9155e4f1d807d8.zip
op-kernel-dev-111abeba67e0dbdc26537429de9155e4f1d807d8.tar.gz
x86/irq: Fix a race 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() to access freed memory. Call irq_domain_reset_irq_data(), which clears the pointer with vector lock held. [ tglx: Free memory outside of lock held region. ] Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Tested-by: Borislav Petkov <bp@alien8.de> Tested-by: Joe Lawrence <joe.lawrence@stratus.com> Cc: Jeremiah Mahler <jmmahler@gmail.com> Cc: andy.shevchenko@gmail.com Cc: Guenter Roeck <linux@roeck-us.net> Cc: stable@vger.kernel.org #4.3+ Link: http://lkml.kernel.org/r/1450880014-11741-3-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kernel/apic/vector.c16
1 files changed, 8 insertions, 8 deletions
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 908cb37..cf1e325 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -226,10 +226,8 @@ 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);
vector = data->cfg.vector;
@@ -239,10 +237,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
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) {
@@ -255,7 +251,6 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
}
}
data->move_in_progress = 0;
- raw_spin_unlock_irqrestore(&vector_lock, flags);
}
void init_irq_alloc_info(struct irq_alloc_info *info,
@@ -276,19 +271,24 @@ void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src)
static void x86_vector_free_irqs(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs)
{
+ struct apic_chip_data *apic_data;
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);
+ apic_data = irq_data->chip_data;
+ irq_domain_reset_irq_data(irq_data);
+ raw_spin_unlock_irqrestore(&vector_lock, flags);
+ free_apic_chip_data(apic_data);
#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);
}
}
}
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