[XS] Change in flashrom[main]: erasure_layout: Fix init_eraseblock segmentation fault

[DigitalDJ (Code Review)]

DigitalDJ has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/84234?usp=email )

Change subject: erasure_layout: Fix init_eraseblock segmentation fault
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erasure_layout: Fix init_eraseblock segmentation fault

Fix a segmentation fault that is caused by accessing an invalid "subedata"
pointer on the last iteration of the init_eraseblock loop. Instead, short
circuit the condition and do not access the invalid pointer if it is the
last sub block.

BUG=https://ticket.coreboot.org/issues/555

Change-Id: I61bf0d93aa9f0b2b420b146be16fcd5124f0dc5d
Signed-off-by: Grant Pannell 
---
M erasure_layout.c
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/34/84234/1

diff --git a/erasure_layout.c b/erasure_layout.c
index a7eaa2d..0a64030 100644
--- a/erasure_layout.c
+++ b/erasure_layout.c
@@ -52,8 +52,8 @@

edata->first_sub_block_index = *sub_block_index;
    struct eraseblock_data *subedata = &layout[idx - 1].layout_list[*sub_block_index];
-	while (subedata->start_addr >= start_addr && subedata->end_addr <= end_addr &&
-		*sub_block_index < layout[idx-1].block_count) {
+	while (*sub_block_index < layout[idx-1].block_count &&
+		subedata->start_addr >= start_addr && subedata->end_addr <= end_addr) {
    	(*sub_block_index)++;
    	subedata++;
    }