Commit dad5ab0d authored by Seunghun Han's avatar Seunghun Han Committed by Ingo Molnar

x86/acpi: Prevent out of bound access caused by broken ACPI tables

The bus_irq argument of mp_override_legacy_irq() is used as the index into
the isa_irq_to_gsi[] array. The bus_irq argument originates from
ACPI_MADT_TYPE_IO_APIC and ACPI_MADT_TYPE_INTERRUPT items in the ACPI
tables, but is nowhere sanity checked.

That allows broken or malicious ACPI tables to overwrite memory, which
might cause malfunction, panic or arbitrary code execution.

Add a sanity check and emit a warning when that triggers.

[ tglx: Added warning and rewrote changelog ]
Signed-off-by: default avatarSeunghun Han <kkamagui@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: security@kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 4c07f904
...@@ -346,6 +346,14 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, ...@@ -346,6 +346,14 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
int pin; int pin;
struct mpc_intsrc mp_irq; struct mpc_intsrc mp_irq;
/*
* Check bus_irq boundary.
*/
if (bus_irq >= NR_IRQS_LEGACY) {
pr_warn("Invalid bus_irq %u for legacy override\n", bus_irq);
return;
}
/* /*
* Convert 'gsi' to 'ioapic.pin'. * Convert 'gsi' to 'ioapic.pin'.
*/ */
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment