[S] Change in flashrom[main]: erasure_layout: do not copy region buffers if they are null

[Alexander Goncharov (Code Review)]

Alexander Goncharov has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/81548?usp=email )

Change subject: erasure_layout: do not copy region buffers if they are null
......................................................................

erasure_layout: do not copy region buffers if they are null

memcpy() function expects 2nd parameter to be non-null. Make sure that
the pointer is null before passing it to the function.

Found-by: scan-build, clang v17.0.6
Signed-off-by: Alexander Goncharov 
Change-Id: I99aad4119f9c11bea75e3419926cc833bc1f68c5
---
M erasure_layout.c
1 file changed, 8 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/48/81548/1

diff --git a/erasure_layout.c b/erasure_layout.c
index 1dd6b60..762cd64 100644
--- a/erasure_layout.c
+++ b/erasure_layout.c
@@ -381,11 +381,15 @@
    }

_end:
-	memcpy(newcontents + region_start, old_start_buf, old_start - region_start);
-	memcpy(newcontents + old_end, old_end_buf, region_end - old_end);
+	if (old_start_buf) {
+		memcpy(newcontents + region_start, old_start_buf, old_start - region_start);
+		free(old_start_buf);
+	}

-	free(old_start_buf);
-	free(old_end_buf);
+	if (old_end_buf) {
+		memcpy(newcontents + old_end, old_end_buf, region_end - old_end);
+		free(old_end_buf);
+	}

msg_cinfo("Erase/write done from %"PRIx32" to %"PRIx32"\n", region_start, region_end);
    return ret;