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authorSeunghun Han <kkamagui@gmail.com>2017-07-18 20:03:51 +0900
committerBen Hutchings <ben@decadent.org.uk>2017-11-11 13:34:24 +0000
commit96301209473afd3f2f274b91cb7082d161b9be65 (patch)
treeae4b821b9902de4387636e6d710709139d407371
parent57f45c30eee35f02adee5d96442e38d6c3884263 (diff)
downloadtip-96301209473afd3f2f274b91cb7082d161b9be65.tar.gz
x86/acpi: Prevent out of bound access caused by broken ACPI tables
Notice: this object is not reachable from any branch.
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: Ben Hutchings <ben@decadent.org.uk>
Notice: this object is not reachable from any branch.
-rw-r--r--arch/x86/kernel/acpi/boot.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 479d03c9c4c3d..6532d9140a0eb 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -952,6 +952,14 @@ void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, u32 gsi)
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);