4.9-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
The backport of upstream commit 45d55e7bac40 ("x86/apic/vector: Fix off by one in error path") missed to fixup the legacy interrupt data which is not longer available upstream.
Handle legacy irq data correctly by clearing the legacy storage to prevent use after free.
Fixes: 7fd133539289 ("x86/apic/vector: Fix off by one in error path") - 4.4.y Fixes: c557481a9491 ("x86/apic/vector: Fix off by one in error path") - 4.9.y Reported-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Thomas Gleixner tglx@linutronix.de Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kernel/apic/vector.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/arch/x86/kernel/apic/vector.c +++ b/arch/x86/kernel/apic/vector.c @@ -93,8 +93,12 @@ out_data: return NULL; }
-static void free_apic_chip_data(struct apic_chip_data *data) +static void free_apic_chip_data(unsigned int virq, struct apic_chip_data *data) { +#ifdef CONFIG_X86_IO_APIC + if (virq < nr_legacy_irqs()) + legacy_irq_data[virq] = NULL; +#endif if (data) { free_cpumask_var(data->domain); free_cpumask_var(data->old_domain); @@ -318,11 +322,7 @@ static void x86_vector_free_irqs(struct 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 + free_apic_chip_data(virq + i, apic_data); } } } @@ -363,7 +363,7 @@ static int x86_vector_alloc_irqs(struct err = assign_irq_vector_policy(virq + i, node, data, info); if (err) { irq_data->chip_data = NULL; - free_apic_chip_data(data); + free_apic_chip_data(virq + i, data); goto error; } }