[coreboot-gerrit] Change in coreboot[master]: commonlib/region: Fix up overflow check in region_is_subregion()

[Julius Werner (Code Review)]

Hello Aaron Durbin,

I'd like you to do a code review. Please visit

https://review.coreboot.org/c/coreboot/+/34892

to review the following change.

Change subject: commonlib/region: Fix up overflow check in region_is_subregion()
......................................................................

commonlib/region: Fix up overflow check in region_is_subregion()

region_is_subregion() checks whether the size of the inner region is
larger than the size of the outer region... which isn't really necessary
because we're already checking the starts and ends of both regions.
Maybe this was added to ensure the inner region doesn't overflow? But
it's not guaranteed to catch that in all cases. Replace it with a proper
overflow check.

Change-Id: I9e442053584a479a323c1fa1c0591934ff83eb10
Signed-off-by: Julius Werner 
---
M src/commonlib/region.c
1 file changed, 2 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/92/34892/1

diff --git a/src/commonlib/region.c b/src/commonlib/region.c
index 541a125..b5858f9 100644
--- a/src/commonlib/region.c
+++ b/src/commonlib/region.c
@@ -27,10 +27,10 @@
    if (region_offset(c) < region_offset(p))
    	return 0;

-	if (region_sz(c) > region_sz(p))
+	if (region_end(c) > region_end(p))
    	return 0;

-	if (region_end(c) > region_end(p))
+	if (region_end(c) < region_offset(c))
    	return 0;

return 1;