diff options
| author | Bjorn Helgaas <bjorn.helgaas@hp.com> | 2008-08-01 15:58:17 -0600 |
|---|---|---|
| committer | Andi Kleen <ak@linux.intel.com> | 2008-08-15 03:17:07 +0200 |
| commit | fa46d3526461e8aa7c0fb39cc1b98ac656695a43 (patch) | |
| tree | 0094d2a1ff5782cdf6f65dcdf8c7c54e0e1bded9 | |
| parent | b635acec48bcaa9183fcbf4e3955616b0d4119b5 (diff) | |
ACPI: bounds check IRQ to prevent memory corruption
acpi_penalize_isa_irq() should validate irq before using it to
index the acpi_irq_penalty[] table.
Here's the path I'm concerned about:
pnpacpi_parse_allocated_irqresource()
{
...
irq = acpi_register_gsi(gsi, triggering, polarity);
if (irq >= 0)
pcibios_penalize_isa_irq(irq, 1);
There's no guarantee that acpi_register_gsi() will return an IRQ
within the bounds of acpi_irq_penalty[].
I have not seen a failure I can attribute to this. However,
ACPI_MAX_IRQS is only 256, and I'm pretty sure ia64 can have
IRQs larger than that.
I think this should go in 2.6.27.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
| -rw-r--r-- | drivers/acpi/pci_link.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/acpi/pci_link.c b/drivers/acpi/pci_link.c index 89f3b2abfdc..cf47805a744 100644 --- a/drivers/acpi/pci_link.c +++ b/drivers/acpi/pci_link.c @@ -849,7 +849,7 @@ static int __init acpi_irq_penalty_update(char *str, int used) if (irq < 0) continue; - if (irq >= ACPI_MAX_IRQS) + if (irq >= ARRAY_SIZE(acpi_irq_penalty)) continue; if (used) @@ -872,10 +872,12 @@ static int __init acpi_irq_penalty_update(char *str, int used) */ void acpi_penalize_isa_irq(int irq, int active) { - if (active) - acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED; - else - acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING; + if (irq >= 0 && irq < ARRAY_SIZE(acpi_irq_penalty)) { + if (active) + acpi_irq_penalty[irq] += PIRQ_PENALTY_ISA_USED; + else + acpi_irq_penalty[irq] += PIRQ_PENALTY_PCI_USING; + } } /* |