From bf39d3283bbc83773459ae5d399ead2bf4452fb7 Mon Sep 17 00:00:00 2001
From: Freya Murphy <freya@freyacat.org>
Date: Sun, 22 Sep 2024 16:44:54 -0400
Subject: [PATCH] fix mem errors

---
 mld/link.c   | 4 ++++
 mld/seg.c    | 5 +++++
 mld/segtab.c | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/mld/link.c b/mld/link.c
index de703c2..5696973 100644
--- a/mld/link.c
+++ b/mld/link.c
@@ -399,6 +399,10 @@ static int relocate_instruction_rela(struct linker *linker,
 	/// get the segment that the symbol is in
 	struct segment_table_entry *ent;
 	const char *segname = seg->obj->shstrtab->data + B32(shdr->sh_name);
+	if (B32(shdr->sh_name) >= seg->obj->shstrtab->len) {
+		ERROR("relocation segment name out of bounds");
+		return M_ERROR;
+	}
 	if (segtab_get(&linker->segments, &ent, segname)) {
 		ERROR("could not locate segment for relocation");
 		return M_ERROR;
diff --git a/mld/seg.c b/mld/seg.c
index 23cf062..ba14cf9 100644
--- a/mld/seg.c
+++ b/mld/seg.c
@@ -43,6 +43,11 @@ static int load_shdr(struct object *obj, struct segment *seg, size_t index)
 		}
 		seg->name = &obj->shstrtab->data[name];
 
+		if (seg->phdr->p_filesz != hdr->sh_size) {
+			ERROR("segment phdr and shdr file sizes to not match");
+			return M_ERROR;
+		}
+
 		// map bytes
 		uint32_t len = B32(hdr->sh_size);
 		uint32_t off = B32(hdr->sh_offset);
diff --git a/mld/segtab.c b/mld/segtab.c
index 22356d5..d62b9a8 100644
--- a/mld/segtab.c
+++ b/mld/segtab.c
@@ -121,12 +121,14 @@ int segtab_ent_push(struct segment_table_entry *ent, struct segment *seg)
 		if (first->align != seg->align) {
 			ERROR("segment '%s' doest not have matching alignment",
 				ent->name);
+			return M_ERROR;
 		}
 		if (first->read != seg->read ||
 			first->write != seg->write ||
 			first->execute != seg->execute) {
 			ERROR("segment '%s' doest not have matching RWX",
 				ent->name);
+			return M_ERROR;
 		}
 	} else {
 		ent->off = seg->new_off;