path: root/arch
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authorSeunghun Han <kkamagui@gmail.com>2017-07-18 20:03:51 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 15:06:07 -0700
commitfa7ddee3485f17c28fe4079954c5716036de6152 (patch)
tree6f78d7f8fb19da0d56f0e71875501bb2e00ef906 /arch
parent62d131ec60cdd8751e40e92b0fb78e30932e6c14 (diff)
x86/acpi: Prevent out of bound access caused by broken ACPI tables
commit dad5ab0db8deac535d03e3fe3d8f2892173fa6a4 upstream. 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: Seunghun Han <kkamagui@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: security@kernel.org Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index e75907601a41..1e5eb9f2ff5f 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -329,6 +329,14 @@ static void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
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'.
ioapic = mp_find_ioapic(gsi);