Commit e4d1544b authored by Jiang Liu's avatar Jiang Liu Committed by Greg Kroah-Hartman

x86/irq: Fix a race in x86_vector_free_irqs()

commit 111abeba upstream.

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: default avatarJiang Liu <jiang.liu@linux.intel.com>
Tested-by: default avatarBorislav Petkov <bp@alien8.de>
Tested-by: default avatarJoe Lawrence <joe.lawrence@stratus.com>
Cc: Jeremiah Mahler <jmmahler@gmail.com>
Cc: andy.shevchenko@gmail.com
Cc: Guenter Roeck <linux@roeck-us.net>
Link: http://lkml.kernel.org/r/1450880014-11741-3-git-send-email-jiang.liu@linux.intel.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 7df19ad4
...@@ -224,10 +224,8 @@ static int assign_irq_vector_policy(int irq, int node, ...@@ -224,10 +224,8 @@ static int assign_irq_vector_policy(int irq, int node,
static void clear_irq_vector(int irq, struct apic_chip_data *data) static void clear_irq_vector(int irq, struct apic_chip_data *data)
{ {
struct irq_desc *desc; struct irq_desc *desc;
unsigned long flags;
int cpu, vector; int cpu, vector;
raw_spin_lock_irqsave(&vector_lock, flags);
BUG_ON(!data->cfg.vector); BUG_ON(!data->cfg.vector);
vector = data->cfg.vector; vector = data->cfg.vector;
...@@ -237,10 +235,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data) ...@@ -237,10 +235,8 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
data->cfg.vector = 0; data->cfg.vector = 0;
cpumask_clear(data->domain); cpumask_clear(data->domain);
if (likely(!data->move_in_progress)) { if (likely(!data->move_in_progress))
raw_spin_unlock_irqrestore(&vector_lock, flags);
return; return;
}
desc = irq_to_desc(irq); desc = irq_to_desc(irq);
for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) { for_each_cpu_and(cpu, data->old_domain, cpu_online_mask) {
...@@ -253,7 +249,6 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data) ...@@ -253,7 +249,6 @@ static void clear_irq_vector(int irq, struct apic_chip_data *data)
} }
} }
data->move_in_progress = 0; data->move_in_progress = 0;
raw_spin_unlock_irqrestore(&vector_lock, flags);
} }
void init_irq_alloc_info(struct irq_alloc_info *info, void init_irq_alloc_info(struct irq_alloc_info *info,
...@@ -274,19 +269,24 @@ void copy_irq_alloc_info(struct irq_alloc_info *dst, struct irq_alloc_info *src) ...@@ -274,19 +269,24 @@ 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, static void x86_vector_free_irqs(struct irq_domain *domain,
unsigned int virq, unsigned int nr_irqs) unsigned int virq, unsigned int nr_irqs)
{ {
struct apic_chip_data *apic_data;
struct irq_data *irq_data; struct irq_data *irq_data;
unsigned long flags;
int i; int i;
for (i = 0; i < nr_irqs; i++) { for (i = 0; i < nr_irqs; i++) {
irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i); irq_data = irq_domain_get_irq_data(x86_vector_domain, virq + i);
if (irq_data && irq_data->chip_data) { if (irq_data && irq_data->chip_data) {
raw_spin_lock_irqsave(&vector_lock, flags);
clear_irq_vector(virq + i, irq_data->chip_data); 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 #ifdef CONFIG_X86_IO_APIC
if (virq + i < nr_legacy_irqs()) if (virq + i < nr_legacy_irqs())
legacy_irq_data[virq + i] = NULL; legacy_irq_data[virq + i] = NULL;
#endif #endif
irq_domain_reset_irq_data(irq_data);
} }
} }
} }
......
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