From: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> [ Upstream commit a4abc6b12eb1f7a533c2e7484cfa555454ff0977 ] nfsd4_process_cb_update() invokes svc_xprt_get(), which increases the refcount of the "c->cn_xprt". The reference counting issue happens in one exception handling path of nfsd4_process_cb_update(). When setup callback client failed, the function forgets to decrease the refcnt increased by svc_xprt_get(), causing a refcnt leak. Fix this issue by calling svc_xprt_put() when setup callback client failed. Signed-off-by: Xiyu Yang <xiyuyang19@xxxxxxxxxxxx> Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/nfsd/nfs4callback.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index afca3287184b..efe55d101b0e 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -1230,6 +1230,8 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) err = setup_callback_client(clp, &conn, ses); if (err) { nfsd4_mark_cb_down(clp, err); + if (c) + svc_xprt_put(c->cn_xprt); return; } } -- 2.25.1