[PATCH 3.8 093/133] nfsd4: buffer-length check for SUPPATTR_EXCLCREAT

[Kamal Mostafa]

3.8.13.22 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: "J. Bruce Fields" <bfields at redhat.com>

commit de3997a7eeb9ea286b15879fdf8a95aae065b4f7 upstream.

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

Cc: Benny Halevy <bhalevy at primarydata.com>
Signed-off-by: J. Bruce Fields <bfields at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/nfsd/nfs4xdr.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 3ed8550..b2d4e3d 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2416,6 +2416,8 @@ 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);
-- 
1.9.1