[PATCH] x86_64: Do more checking in the SRAT header code

 - Check if the processor/memory affinity entries are long enough
   according to the ACPI 3.0 spec.
 - Ignore memory affinity entries that define a zero length region.

All based on BIOS issues found in the field @)

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 15 insertions, 4 deletions

diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c
index 3bd827f5611f..cd25300726fc 100644
--- a/arch/x86_64/mm/srat.c
+++ b/arch/x86_64/mm/srat.c
@@ -135,7 +135,12 @@ void __init
 acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
 {
         int pxm, node;
-        if (srat_disabled() || pa->flags.enabled == 0)
+        if (srat_disabled())
+                return;
+        if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) {                bad_srat();
+                return;
+        }
+        if (pa->flags.enabled == 0)
                 return;
         pxm = pa->proximity_domain;
         node = setup_node(pxm);
@@ -159,8 +164,16 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
         int node, pxm;
         int i;
 
-        if (srat_disabled() || ma->flags.enabled == 0)
+        if (srat_disabled())
                 return;
+        if (ma->header.length != sizeof(struct acpi_table_memory_affinity)) {
+                bad_srat();
+                return;
+        }
+        if (ma->flags.enabled == 0)
+                return;
+        start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
+        end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
         pxm = ma->proximity_domain;
         node = setup_node(pxm);
         if (node < 0) {
@@ -168,8 +181,6 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma)
                 bad_srat();
                 return;
         }
-        start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32);
-        end = start + (ma->length_lo | ((u64)ma->length_hi << 32));
         /* It is fine to add this area to the nodes data it will be used later*/
         if (ma->flags.hot_pluggable == 1)
                 printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n",