nfsd4: disallow SEEK with special stateids
If the client uses a special stateid then we'll pass a NULL file to
vfs_llseek.
Fixes: 24bab491220f " NFSD: Implement SEEK"
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: stable@vger.kernel.org
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index d0848fc..4a8314f 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1071,6 +1071,8 @@
dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
return status;
}
+ if (!file)
+ return nfserr_bad_stateid;
switch (seek->seek_whence) {
case NFS4_CONTENT_DATA: