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authorChuck Lever <chuck.lever@oracle.com>2020-10-02 00:58:56 +0200
committerJ. Bruce Fields <bfields@redhat.com>2020-10-02 15:37:41 +0200
commit6b3dccd48de8a4c650b01499a0b09d1e2279649e (patch)
tree3bcdd92076c06f12633bf35bf9bbafe2e12229c2
parentnfsd: rq_lease_breaker cleanup (diff)
downloadlinux-6b3dccd48de8a4c650b01499a0b09d1e2279649e.tar.xz
linux-6b3dccd48de8a4c650b01499a0b09d1e2279649e.zip
NFSD: Add missing NFSv2 .pc_func methods
There's no protection in nfsd_dispatch() against a NULL .pc_func helpers. A malicious NFS client can trigger a crash by invoking the unused/unsupported NFSv2 ROOT or WRITECACHE procedures. The current NFSD dispatcher does not support returning a void reply to a non-NULL procedure, so the reply to both of these is wrong, for the moment. Cc: <stable@vger.kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--fs/nfsd/nfsproc.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c
index 6e0b066480c5..6d1b3af40a4f 100644
--- a/fs/nfsd/nfsproc.c
+++ b/fs/nfsd/nfsproc.c
@@ -118,6 +118,13 @@ done:
return nfsd_return_attrs(nfserr, resp);
}
+/* Obsolete, replaced by MNTPROC_MNT. */
+static __be32
+nfsd_proc_root(struct svc_rqst *rqstp)
+{
+ return nfs_ok;
+}
+
/*
* Look up a path name component
* Note: the dentry in the resp->fh may be negative if the file
@@ -203,6 +210,13 @@ nfsd_proc_read(struct svc_rqst *rqstp)
return fh_getattr(&resp->fh, &resp->stat);
}
+/* Reserved */
+static __be32
+nfsd_proc_writecache(struct svc_rqst *rqstp)
+{
+ return nfs_ok;
+}
+
/*
* Write data to a file
* N.B. After this call resp->fh needs an fh_put
@@ -617,6 +631,7 @@ static const struct svc_procedure nfsd_procedures2[18] = {
.pc_xdrressize = ST+AT,
},
[NFSPROC_ROOT] = {
+ .pc_func = nfsd_proc_root,
.pc_decode = nfssvc_decode_void,
.pc_encode = nfssvc_encode_void,
.pc_argsize = sizeof(struct nfsd_void),
@@ -654,6 +669,7 @@ static const struct svc_procedure nfsd_procedures2[18] = {
.pc_xdrressize = ST+AT+1+NFSSVC_MAXBLKSIZE_V2/4,
},
[NFSPROC_WRITECACHE] = {
+ .pc_func = nfsd_proc_writecache,
.pc_decode = nfssvc_decode_void,
.pc_encode = nfssvc_encode_void,
.pc_argsize = sizeof(struct nfsd_void),