From: MikeCAT <mikecat@users.noreply.github.com>
Date: Sat, 19 Dec 2015 15:04:52 +0000 (+0900)
Subject: add check for wrapping of address + size in exec()
X-Git-Url: https://git.devinivas.org/?a=commitdiff_plain;h=5625ae49731d25e85bcaf8c8cc8f843969588981;p=cs3210-lab1.git

add check for wrapping of address + size in exec()
---

diff --git a/exec.c b/exec.c
index e5d1816..d56ee1d 100644
--- a/exec.c
+++ b/exec.c
@@ -44,6 +44,8 @@ exec(char *path, char **argv)
       continue;
     if(ph.memsz < ph.filesz)
       goto bad;
+    if(ph.vaddr + ph.memsz < ph.vaddr)
+      goto bad;
     if((sz = allocuvm(pgdir, sz, ph.vaddr + ph.memsz)) == 0)
       goto bad;
     if(ph.vaddr % PGSIZE != 0)