From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Laight" Subject: RE: [patch] Fix handling of overlength pathname in AF_UNIX sun_path Date: Wed, 18 Apr 2012 09:17:26 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: , , , , , , , To: "Carlos O'Donell" , "David Miller" Return-path: Content-class: urn:content-classes:message In-Reply-To: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org > > Why not have: > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index d510353..f9f77a7 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -216,6 +216,9 @@ static int unix_mkname(struct sockaddr_un > *sunaddr, int len, unsigned *hashp) > */ > ((char *)sunaddr)[len] = 0; > len = strlen(sunaddr->sun_path)+1+sizeof(short); > + /* No null terminator was found in the path. */ > + if (len > sizeof(*sunaddr)) > + return -EINVAL; > return len; That could generate a kernel page fault! (Depending on what follows (or rather doesn't follow!) sun_path.) You'd need to use memchr() not strlen(). David From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Laight" Subject: RE: [patch] Fix handling of overlength pathname in AF_UNIX sun_path Date: Wed, 18 Apr 2012 09:17:26 +0100 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: Content-class: urn:content-classes:message In-Reply-To: Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Carlos O'Donell , David Miller Cc: mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, penguin-kernel-1yMVhJb1mP/7nzcFbJAaVXf5DAMn2ifp@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yoshfuji-VfPWfsRibaP+Ru+s062T9g@public.gmane.org, jengelh-nopoi9nDyk+ELgA04lAiVw@public.gmane.org, w@1wt.eu, alan-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org List-Id: linux-api@vger.kernel.org > > Why not have: > > diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c > index d510353..f9f77a7 100644 > --- a/net/unix/af_unix.c > +++ b/net/unix/af_unix.c > @@ -216,6 +216,9 @@ static int unix_mkname(struct sockaddr_un > *sunaddr, int len, unsigned *hashp) > */ > ((char *)sunaddr)[len] = 0; > len = strlen(sunaddr->sun_path)+1+sizeof(short); > + /* No null terminator was found in the path. */ > + if (len > sizeof(*sunaddr)) > + return -EINVAL; > return len; That could generate a kernel page fault! (Depending on what follows (or rather doesn't follow!) sun_path.) You'd need to use memchr() not strlen(). David