trusted-keys: check for NULL before using it

TSS_rawhmac() checks for data != NULL before using it.
We should do the same thing for TSS_authhmac().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/security/keys/trusted_defined.c b/security/keys/trusted_defined.c
index 7b2179589063..f7d06776faf0 100644
--- a/security/keys/trusted_defined.c
+++ b/security/keys/trusted_defined.c
@@ -148,6 +148,11 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
                 if (dlen == 0)
                         break;
                 data = va_arg(argp, unsigned char *);
+                if (!data) {
+                        ret = -EINVAL;
+                        va_end(argp);
+                        goto out;
+                }
                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
                 if (ret < 0) {
                         va_end(argp);