From: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
To: Assar <assar@permabit.com>, Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Peter Staubach <staubach@redhat.com>,
Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org
Subject: [PATCH] nfs client: handle long symlinks properly
Date: Thu, 22 Sep 2005 13:14:20 -0300 [thread overview]
Message-ID: <20050922161420.GC5588@dmt.cnet> (raw)
commit 87e03738fc15dc3ea4acde3a5dcb5f84b6b6152b
tree be323c0a65d7e380ad04cad1c3a80015a82056dd
parent bb52ef60b5caa8f973523eda15d3c3941f298e63
author Assar <assar@permabit.com> Wed, 14 Sep 2005 16:59:25 -0400
committer Marcelo Tosatti <marcelo@dmt.cnet> Thu, 22 Sep 2005 13:11:18 -0300
[PATCH] nfs client: handle long symlinks properly
In 2.4.31, the v2/3 nfs readlink accepts too long symlinks.
I have tested this by having a server return long symlinks.
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -571,8 +571,11 @@ nfs_xdr_readlinkres(struct rpc_rqst *req
strlen = (u32*)kmap(rcvbuf->pages[0]);
/* Convert length of symlink */
len = ntohl(*strlen);
- if (len > rcvbuf->page_len)
- len = rcvbuf->page_len;
+ if (len >= rcvbuf->page_len - sizeof(u32) || len > NFS2_MAXPATHLEN) {
+ printk(KERN_WARNING "NFS: server returned giant symlink!\n");
+ kunmap(rcvbuf->pages[0]);
+ return -ENAMETOOLONG;
+ }
*strlen = len;
/* NULL terminate the string we got */
string = (char *)(strlen + 1);
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -759,8 +759,11 @@ nfs3_xdr_readlinkres(struct rpc_rqst *re
strlen = (u32*)kmap(rcvbuf->pages[0]);
/* Convert length of symlink */
len = ntohl(*strlen);
- if (len > rcvbuf->page_len)
- len = rcvbuf->page_len;
+ if (len >= rcvbuf->page_len - sizeof(u32)) {
+ printk(KERN_WARNING "NFS: server returned giant symlink!\n");
+ kunmap(rcvbuf->pages[0]);
+ return -ENAMETOOLONG;
+ }
*strlen = len;
/* NULL terminate the string we got */
string = (char *)(strlen + 1);
next reply other threads:[~2005-09-22 16:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-22 16:14 Marcelo Tosatti [this message]
2005-09-22 16:33 ` Trond Myklebust
2005-09-22 16:38 ` Assar
2005-09-22 16:55 ` Trond Myklebust
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