4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
commit 111abeba67e0dbdc26537429de9155e4f1d807d8 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: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Tested-by: Borislav Petkov <bp@xxxxxxxxx>
Tested-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx>
Cc: Jeremiah Mahler <jmmahler@xxxxxxxxx>
Cc: andy.shevchenko@xxxxxxxxx
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1450880014-11741-3-git-send-email-jiang.liu@xxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/apic/vector.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -224,10 +224,8 @@ static int assign_irq_vector_policy(int
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;
@@ -237,10 +235,8 @@ static void clear_irq_vector(int irq, st
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) {
@@ -253,7 +249,6 @@ static void clear_irq_vector(int irq, st
}
}
data->move_in_progress = 0;
- raw_spin_unlock_irqrestore(&vector_lock, flags);
}
void init_irq_alloc_info(struct irq_alloc_info *info,
@@ -274,19 +269,24 @@ void copy_irq_alloc_info(struct irq_allo
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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