From e7f5fdf53ee68025f3ef2688e2f27ccb0082db83 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Thu, 27 Jul 2023 17:59:22 -0400
Subject: [PATCH] pe-relocate: Ensure nothing else implements CVE-2023-40550

In CVE-2023-40550, we scan the section headers for the section
name without having verified that the section header is actually in the
binary.

This patch adds such verification to read_headers()

Signed-off-by: Peter Jones <pjones@redhat.com>
---
 pe-relocate.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/pe-relocate.c b/pe-relocate.c
index 1723642..cb7a02c 100644
--- a/pe.c
+++ b/pe.c
@@ -472,6 +472,13 @@ read_header(void *data, unsigned int datasize,
 		return EFI_UNSUPPORTED;
 	}
 
+	if (checked_mul((size_t)context->NumberOfSections, sizeof(EFI_IMAGE_SECTION_HEADER), &tmpsz0) ||
+	    checked_add(tmpsz0, SectionHeaderOffset, &tmpsz0) ||
+	    (tmpsz0 > datasize)) {
+		perror(L"Image sections overflow section headers\n");
+		return EFI_UNSUPPORTED;
+	}
+
 	if (checked_sub((size_t)(uintptr_t)PEHdr, (size_t)(uintptr_t)data, &tmpsz0) ||
 	    checked_add(tmpsz0, sizeof(EFI_IMAGE_OPTIONAL_HEADER_UNION), &tmpsz0) ||
 	    (tmpsz0 > datasize)) {
-- 
2.33.0