6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: NeilBrown <neilb@xxxxxxx>
[ Upstream commit 7917f01a286ce01e9c085e24468421f596ee1a0c ]
A recent patch inadvertently broke callbacks for NFSv4.0.
In the 4.0 case we do not expect a session to be found but still need to
call setup_callback_client() which will not try to dereference it.
This patch moves the check for failure to find a session into the 4.1+
branch of setup_callback_client()
Fixes: 1e02c641c3a4 ("NFSD: Prevent NULL dereference in nfsd4_process_cb_update()")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/nfsd/nfs4callback.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index a6dc8c479a4b..d2885dd4822d 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -986,7 +986,7 @@ static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *c
args.authflavor = clp->cl_cred.cr_flavor;
clp->cl_cb_ident = conn->cb_ident;
} else {
- if (!conn->cb_xprt)
+ if (!conn->cb_xprt || !ses)
return -EINVAL;
clp->cl_cb_session = ses;
args.bc_xprt = conn->cb_xprt;
@@ -1379,8 +1379,6 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
ses = c->cn_session;
}
spin_unlock(&clp->cl_lock);
- if (!c)
- return;
err = setup_callback_client(clp, &conn, ses);
if (err) {
--
2.39.5
