From: miod <miod@openbsd.org>
Date: Sun, 18 May 2014 21:18:07 +0000 (+0000)
Subject: Correctly handle files smaller than an ELF header; reported by drahn@bitrig
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2756da3cc0c8ef9fe99dfa96f2f8670fcb6e8e28;p=openbsd

Correctly handle files smaller than an ELF header; reported by drahn@bitrig
---

diff --git a/usr.sbin/mkuboot/mkuboot.c b/usr.sbin/mkuboot/mkuboot.c
index a3c95b9da31..8ecb79dd790 100644
--- a/usr.sbin/mkuboot/mkuboot.c
+++ b/usr.sbin/mkuboot/mkuboot.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mkuboot.c,v 1.3 2013/10/28 09:00:06 patrick Exp $	*/
+/*	$OpenBSD: mkuboot.c,v 1.4 2014/05/18 21:18:07 miod Exp $	*/
 
 /*
  * Copyright (c) 2008 Mark Kettenis
@@ -285,12 +285,10 @@ is_elf(int ifd, const char *iname)
 	nbytes = read(ifd, &ehdr, sizeof ehdr);
 	if (nbytes == -1)
 		err(1, "%s", iname);
-	if (nbytes != sizeof ehdr)
-		return 0;
-
 	if (lseek(ifd, 0, SEEK_SET) != 0)
 		err(1, "%s", iname);
-	if (!IS_ELF(ehdr))
+
+	if (nbytes != sizeof ehdr || !IS_ELF(ehdr))
 		return 0;
 
 	if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)