tool: ifwitool: Fix buffer overflow

An incorrect 1st parameter is passed to the fix_member()
 function. Should use a pointer to the beginning of the parent structure
 (bpdt or subpart_dir, because are boxed), not to their fields. Otherwise,
 this leads to an overrun of the structure boundary, since in the
 fix_member() function, an 'offset' is made, relative to the 1st argument,
 which itself is an 'offset' from the beginning of the structure.

Signed-off-by: Mikhail Ilin <ilin.mikhail.ol@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 19 insertions, 25 deletions

diff --git a/tools/ifwitool.c b/tools/ifwitool.c
index a06eb7f..3159186 100644
--- a/tools/ifwitool.c
+++ b/tools/ifwitool.c
@@ -1441,23 +1441,20 @@ static void bpdt_fixup_write_buffer(struct buffer *buf)
 
 	size_t offset = 0;
 
-	offset = fix_member(&h->signature, offset, sizeof(h->signature));
-	offset = fix_member(&h->descriptor_count, offset,
-			    sizeof(h->descriptor_count));
-	offset = fix_member(&h->bpdt_version, offset, sizeof(h->bpdt_version));
-	offset = fix_member(&h->xor_redundant_block, offset,
-			    sizeof(h->xor_redundant_block));
-	offset = fix_member(&h->ifwi_version, offset, sizeof(h->ifwi_version));
-	offset = fix_member(&h->fit_tool_version, offset,
-			    sizeof(h->fit_tool_version));
+	offset = fix_member(&s, offset, sizeof(h->signature));
+	offset = fix_member(&s, offset, sizeof(h->descriptor_count));
+	offset = fix_member(&s, offset, sizeof(h->bpdt_version));
+	offset = fix_member(&s, offset, sizeof(h->xor_redundant_block));
+	offset = fix_member(&s, offset, sizeof(h->ifwi_version));
+	offset = fix_member(&s, offset, sizeof(h->fit_tool_version));
 
 	uint32_t i;
 
 	for (i = 0; i < count; i++) {
-		offset = fix_member(&e[i].type, offset, sizeof(e[i].type));
-		offset = fix_member(&e[i].flags, offset, sizeof(e[i].flags));
-		offset = fix_member(&e[i].offset, offset, sizeof(e[i].offset));
-		offset = fix_member(&e[i].size, offset, sizeof(e[i].size));
+		offset = fix_member(&s, offset, sizeof(e[i].type));
+		offset = fix_member(&s, offset, sizeof(e[i].flags));
+		offset = fix_member(&s, offset, sizeof(e[i].offset));
+		offset = fix_member(&s, offset, sizeof(e[i].size));
 	}
 }
 
@@ -1657,24 +1654,21 @@ static void subpart_dir_fixup_write_buffer(struct buffer *buf)
 	size_t count = h->num_entries;
 	size_t offset = 0;
 
-	offset = fix_member(&h->marker, offset, sizeof(h->marker));
-	offset = fix_member(&h->num_entries, offset, sizeof(h->num_entries));
-	offset = fix_member(&h->header_version, offset,
-			    sizeof(h->header_version));
-	offset = fix_member(&h->entry_version, offset,
-			    sizeof(h->entry_version));
-	offset = fix_member(&h->header_length, offset,
-			    sizeof(h->header_length));
-	offset = fix_member(&h->checksum, offset, sizeof(h->checksum));
+	offset = fix_member(&s, offset, sizeof(h->marker));
+	offset = fix_member(&s, offset, sizeof(h->num_entries));
+	offset = fix_member(&s, offset, sizeof(h->header_version));
+	offset = fix_member(&s, offset, sizeof(h->entry_version));
+	offset = fix_member(&s, offset, sizeof(h->header_length));
+	offset = fix_member(&s, offset, sizeof(h->checksum));
 	offset += sizeof(h->name);
 
 	uint32_t i;
 
 	for (i = 0; i < count; i++) {
 		offset += sizeof(e[i].name);
-		offset = fix_member(&e[i].offset, offset, sizeof(e[i].offset));
-		offset = fix_member(&e[i].length, offset, sizeof(e[i].length));
-		offset = fix_member(&e[i].rsvd, offset, sizeof(e[i].rsvd));
+		offset = fix_member(&s, offset, sizeof(e[i].offset));
+		offset = fix_member(&s, offset, sizeof(e[i].length));
+		offset = fix_member(&s, offset, sizeof(e[i].rsvd));
 	}
 }