[PATCH v3] nfsd: Fix cld_net->cn_tfm initialization

[PATCH v3] nfsd: Fix cld_net->cn_tfm initialization

[Scott Mayhew]

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@audible.transient.net>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
---
 fs/nfsd/nfs4recover.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index cdc75ad4438b..c35c0ebaf722 100644
--- 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)
-- 
2.17.2

Re: [PATCH v3] nfsd: Fix cld_net->cn_tfm initialization

[J. Bruce Fields]

Thanks, applied.--b.

On Tue, Nov 12, 2019 at 02:01:43PM -0500, Scott Mayhew wrote:
> 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@audible.transient.net>
> Signed-off-by: Scott Mayhew <smayhew@redhat.com>
> ---
>  fs/nfsd/nfs4recover.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index cdc75ad4438b..c35c0ebaf722 100644
> --- 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)
> -- 
> 2.17.2