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x86/irq: Fix a race in x86_vector_free_irqs()

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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>
This commit is contained in:
Jiang Liu 2015-12-31 16:30:44 +00:00 committed by Thomas Gleixner
parent e23b257c29
commit 111abeba67
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
arch/x86/kernel/apic/vector.c
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@ -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);
}
}
}