[PATCH 4.9 32/70] NFSv4.0 fix client reference leak in callback

Greg Kroah-Hartman
2018-09-17T22:55:00Z

From: Olga Kornievskaia <kolga@netapp.com>

[ Upstream commit 32cd3ee511f4e07ca25d71163b50e704808d22f4 ]

If there is an error during processing of a callback message, it leads
to refrence leak on the client structure and eventually an unclean
superblock.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/nfs/callback_xdr.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

--- a/fs/nfs/callback_xdr.c
+++ b/fs/nfs/callback_xdr.c
@@ -968,16 +968,21 @@ static __be32 nfs4_callback_compound(str

if (hdr_arg.minorversion == 0) {
cps.clp = nfs4_find_client_ident(SVC_NET(rqstp), hdr_arg.cb_ident);
- if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp))
+ if (!cps.clp || !check_gss_callback_principal(cps.clp, rqstp)) {
+ if (cps.clp)
+ nfs_put_client(cps.clp);
goto out_invalidcred;
+ }
}

cps.minorversion = hdr_arg.minorversion;
hdr_res.taglen = hdr_arg.taglen;
hdr_res.tag = hdr_arg.tag;
- if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0)
+ if (encode_compound_hdr_res(&xdr_out, &hdr_res) != 0) {
+ if (cps.clp)
+ nfs_put_client(cps.clp);
return rpc_system_err;
-
+ }
while (status == 0 && nops != hdr_arg.nops) {
status = process_op(nops, rqstp, &xdr_in,
argp, &xdr_out, resp, &cps);