[PATCH 5.4 105/203] nfsd: Fix cld_net->cn_tfm initialization

From: Greg Kroah-Hartman
Date: Thu Jan 16 2020 - 18:24:02 EST


From: Scott Mayhew <smayhew@xxxxxxxxxx>

commit 18b9a895e652979b70f9c20565394a69354dfebc upstream.

Don't assign an error pointer to cld_net->cn_tfm, otherwise an oops will
occur in nfsd4_remove_cld_pipe().

Also, move the initialization of cld_net->cn_tfm so that it occurs after
the check to see if nfsdcld is running. This is necessary because
nfsd4_client_tracking_init() looks for -ETIMEDOUT to determine whether
to use the "old" nfsdcld tracking ops.

Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
Reported-by: Jamie Heilman <jamie@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/nfsd/nfs4recover.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -1578,6 +1578,7 @@ nfsd4_cld_tracking_init(struct net *net)
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
bool running;
int retries = 10;
+ struct crypto_shash *tfm;

status = nfs4_cld_state_init(net);
if (status)
@@ -1586,11 +1587,6 @@ nfsd4_cld_tracking_init(struct net *net)
status = __nfsd4_init_cld_pipe(net);
if (status)
goto err_shutdown;
- nn->cld_net->cn_tfm = crypto_alloc_shash("sha256", 0, 0);
- if (IS_ERR(nn->cld_net->cn_tfm)) {
- status = PTR_ERR(nn->cld_net->cn_tfm);
- goto err_remove;
- }

/*
* rpc pipe upcalls take 30 seconds to time out, so we don't want to
@@ -1607,6 +1603,12 @@ nfsd4_cld_tracking_init(struct net *net)
status = -ETIMEDOUT;
goto err_remove;
}
+ tfm = crypto_alloc_shash("sha256", 0, 0);
+ if (IS_ERR(tfm)) {
+ status = PTR_ERR(tfm);
+ goto err_remove;
+ }
+ nn->cld_net->cn_tfm = tfm;

status = nfsd4_cld_get_version(nn);
if (status == -EOPNOTSUPP)