From 90bab90832d1f3863d8345bcc2a2e5f59c270af8 Mon Sep 17 00:00:00 2001
From: rsc <rsc>
Date: Sun, 31 May 2009 02:11:27 +0000
Subject: [PATCH] exec sanity check

---
 exec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exec.c b/exec.c
index 98c5d4c..1c653de 100644
--- a/exec.c
+++ b/exec.c
@@ -62,7 +62,7 @@ exec(char *path, char **argv)
       goto bad;
     if(ph.type != ELF_PROG_LOAD)
       continue;
-    if(ph.va + ph.memsz > sz)
+    if(ph.va + ph.memsz < ph.va || ph.va + ph.memsz > sz || ph.memsz < ph.filesz)
       goto bad;
     if(readi(ip, mem + ph.va, ph.offset, ph.filesz) != ph.filesz)
       goto bad;