diff --git a/sys/kern/link_elf_obj.c b/sys/kern/link_elf_obj.c
--- a/sys/kern/link_elf_obj.c
+++ b/sys/kern/link_elf_obj.c
@@ -548,7 +548,7 @@
 		error = ENOEXEC;
 		goto out;
 	}
-	if (symstrindex < 0 || symstrindex > hdr->e_shnum ||
+	if (symstrindex < 0 || symstrindex >= hdr->e_shnum ||
 	    shdr[symstrindex].sh_type != SHT_STRTAB) {
 		link_elf_obj_error(filename, "file has invalid symbol strings");
 		error = ENOEXEC;
@@ -601,6 +601,7 @@
 	/* Do we have a string table for the section names?  */
 	shstrindex = -1;
 	if (hdr->e_shstrndx != 0 &&
+	    hdr->e_shstrndx < hdr->e_shnum &&
 	    shdr[hdr->e_shstrndx].sh_type == SHT_STRTAB) {
 		shstrindex = hdr->e_shstrndx;
 		ef->shstrcnt = shdr[shstrindex].sh_size;