[Qemu-devel] [PATCH] target-s390x: Only access allocated storage keys

[Alexander Graf]

We allocate ram_size / PAGE_SIZE storage keys, so we need to make sure that
we only access that many. Unfortunately the code can overrun this array by
one, potentially overwriting unrelated memory.

Fix it by limiting storage keys to their scope.

Signed-off-by: Alexander Graf <address@hidden>
---
 target-s390x/mmu_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target-s390x/mmu_helper.c b/target-s390x/mmu_helper.c
index e8dcd0c..815ff42 100644
--- a/target-s390x/mmu_helper.c
+++ b/target-s390x/mmu_helper.c
@@ -358,7 +358,7 @@ int mmu_translate(CPUS390XState *env, target_ulong vaddr, 
int rw, uint64_t asc,
     /* Convert real address -> absolute address */
     *raddr = mmu_real2abs(env, *raddr);
 
-    if (*raddr <= ram_size) {
+    if (*raddr < ram_size) {
         sk = &env->storage_keys[*raddr / TARGET_PAGE_SIZE];
         if (*flags & PAGE_READ) {
             *sk |= SK_R;
-- 
2.2.1