[PATCH 5.4 177/203] NFSD fixing possible null pointer derefering in copy offload

[Greg Kroah-Hartman]

From: Olga Kornievskaia <olga.kornievskaia@xxxxxxxxx>

commit 18f428d4e2f7eff162d80b2b21689496c4e82afd upstream.

Static checker revealed possible error path leading to possible
NULL pointer dereferencing.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Fixes: e0639dc5805a: ("NFSD introduce async copy feature")
Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/nfsd/nfs4proc.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1298,7 +1298,8 @@ nfsd4_copy(struct svc_rqst *rqstp, struc
 out:
 	return status;
 out_err:
-	cleanup_async_copy(async_copy);
+	if (async_copy)
+		cleanup_async_copy(async_copy);
 	goto out;
 }