nfsd4: buffer-length check for SUPPATTR_EXCLCREAT

commit de3997a7eeb9ea286b15879fdf8a95aae065b4f7 upstream.

This was an omission from 8c18f2052e756e7d5dea712fc6e7ed70c00e8a39
"nfsd41: SUPPATTR_EXCLCREAT attribute".

Cc: Benny Halevy <bhalevy@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 582321a978b0cbba31fd26d92bc9d8ec93ad4502..d7ea1938cdee3a721f1f991fc9de955d4429968c 100644 (file)
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2401,6 +2401,8 @@ out_acl:
                WRITE64(stat.ino);
        }
        if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
+               if ((buflen -= 16) < 0)
+                       goto out_resource;
                WRITE32(3);
                WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0);
                WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD1);