[coreboot-gerrit] Change in ...coreboot[master]: nb/intel/nehalem: Prevent out of bounds read

[Jacob Garber (Code Review)]

Jacob Garber has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/33383

Change subject: nb/intel/nehalem: Prevent out of bounds read
......................................................................

nb/intel/nehalem: Prevent out of bounds read

Check that clock_speed_index is non-zero before decrementing it, else we
will get a very large out of bounds array access.

Change-Id: Ic8ed1293adfe0866781bd638323977abd110777e
Signed-off-by: Jacob Garber 
Found-by: Coverity CID 1229675
---
M src/northbridge/intel/nehalem/raminit.c
1 file changed, 2 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/83/33383/1

diff --git a/src/northbridge/intel/nehalem/raminit.c b/src/northbridge/intel/nehalem/raminit.c
index 15d6abb..72a2c57 100644
--- a/src/northbridge/intel/nehalem/raminit.c
+++ b/src/northbridge/intel/nehalem/raminit.c
@@ -598,7 +598,8 @@
    for (clock_speed_index = 0; clock_speed_index < 3; clock_speed_index++) {
    	if (cycletime == min_cycletime[clock_speed_index])
    		break;
-		if (cycletime > min_cycletime[clock_speed_index]) {
+		if (cycletime > min_cycletime[clock_speed_index] &&
+				clock_speed_index != 0) {
    		clock_speed_index--;
    		cycletime = min_cycletime[clock_speed_index];
    		break;