[PATCH][next] NFS: Add missing null check for failed allocation

[Colin King]

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently the allocation of buf is not being null checked and
a null pointer dereference can occur when the memory allocation fails.
Fix this by adding a check and returning -ENOMEM.

Addresses-Coverity: ("Dereference null return")
Fixes: 6d972518b821 ("NFS: Add fs_context support.")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
 fs/nfs/nfs4namespace.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 10e9e1887841..de6875a9b391 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -137,6 +137,9 @@ static int nfs4_validate_fspath(struct dentry *dentry,
 	int n;
 
 	buf = kmalloc(4096, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
 	path = nfs4_path(dentry, buf, 4096);
 	if (IS_ERR(path)) {
 		kfree(buf);
-- 
2.24.0