The code checks each fragment mark to see if it's valid; if the fragment

is less than NFS_MINPACKET or greater than NFS_MAXPACKET in size, it
barfs and, I think, drops the connection.

However, there's no guarantee that in a multi-fragment RPC, all the
fragments will be at least as large as NFS_MINPACKET.

In fact, with the version of "tclnfs" we have here, which supports NFS
over TCP, at least when built under SunOS 4.1.3 (i.e., with 4.1.3's
user-mode ONC RPC library), I can *repeatably* cause "tclnfs" to send a
request with more than one fragment, one of which is only 8 bytes long.
I just do a 3877-byte write to a file, at an offset of 0.

The check that "slp->ns_reclen" is greater than or equal to
NFS_MINPACKET serves no useful purpose - if the NFS server code can't
handle packets < NFS_MINPACKET bytes, it can't handle them over *any*
protocol, so the check has to be done above the RPC-over-TCP layer - and
should be removed.
Obtained from: Fix from Guy Harris, forwarded by Rick Macklem.
This commit is contained in:
Kirk McKusick 1998-09-29 22:33:05 +00:00
parent e5b118dd3d
commit 96438eb911
3 changed files with 6 additions and 6 deletions

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* @(#)nfs_socket.c 8.5 (Berkeley) 3/30/95
* $Id: nfs_socket.c,v 1.44 1998/08/23 03:07:16 wollman Exp $
* $Id: nfs_socket.c,v 1.45 1998/09/07 05:42:15 bde Exp $
*/
/*
@ -2125,7 +2125,7 @@ nfsrv_getstream(slp, waitflag)
slp->ns_flag |= SLP_LASTFRAG;
else
slp->ns_flag &= ~SLP_LASTFRAG;
if (slp->ns_reclen < NFS_MINPACKET || slp->ns_reclen > NFS_MAXPACKET) {
if (slp->ns_reclen > NFS_MAXPACKET) {
slp->ns_flag &= ~SLP_GETSTREAM;
return (EPERM);
}

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* @(#)nfs_socket.c 8.5 (Berkeley) 3/30/95
* $Id: nfs_socket.c,v 1.44 1998/08/23 03:07:16 wollman Exp $
* $Id: nfs_socket.c,v 1.45 1998/09/07 05:42:15 bde Exp $
*/
/*
@ -2125,7 +2125,7 @@ nfsrv_getstream(slp, waitflag)
slp->ns_flag |= SLP_LASTFRAG;
else
slp->ns_flag &= ~SLP_LASTFRAG;
if (slp->ns_reclen < NFS_MINPACKET || slp->ns_reclen > NFS_MAXPACKET) {
if (slp->ns_reclen > NFS_MAXPACKET) {
slp->ns_flag &= ~SLP_GETSTREAM;
return (EPERM);
}

View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* @(#)nfs_socket.c 8.5 (Berkeley) 3/30/95
* $Id: nfs_socket.c,v 1.44 1998/08/23 03:07:16 wollman Exp $
* $Id: nfs_socket.c,v 1.45 1998/09/07 05:42:15 bde Exp $
*/
/*
@ -2125,7 +2125,7 @@ nfsrv_getstream(slp, waitflag)
slp->ns_flag |= SLP_LASTFRAG;
else
slp->ns_flag &= ~SLP_LASTFRAG;
if (slp->ns_reclen < NFS_MINPACKET || slp->ns_reclen > NFS_MAXPACKET) {
if (slp->ns_reclen > NFS_MAXPACKET) {
slp->ns_flag &= ~SLP_GETSTREAM;
return (EPERM);
}