Bluetooth: allocate data for kpp on heap

Bluetooth would crash when computing ECDH keys with kpp
if VMAP_STACK is enabled. Fix by allocating data passed
to kpp on heap.

Fixes: 58771c1c ("Bluetooth: convert smp and selftest to crypto kpp
API")
Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 17 insertions, 5 deletions

diff --git a/net/bluetooth/selftest.c b/net/bluetooth/selftest.c
index efef2815646e..ee92c925ecc5 100644
--- a/net/bluetooth/selftest.c
+++ b/net/bluetooth/selftest.c
@@ -142,18 +142,30 @@ static int __init test_ecdh_sample(const u8 priv_a[32], const u8 priv_b[32],
 				   const u8 pub_a[64], const u8 pub_b[64],
 				   const u8 dhkey[32])
 {
-	u8 dhkey_a[32], dhkey_b[32];
+	u8 *tmp, *dhkey_a, *dhkey_b;
+	int ret = 0;
+
+	tmp = kmalloc(64, GFP_KERNEL);
+	if (!tmp)
+		return -EINVAL;
+
+	dhkey_a = &tmp[0];
+	dhkey_b = &tmp[32];
 
 	compute_ecdh_secret(pub_b, priv_a, dhkey_a);
 	compute_ecdh_secret(pub_a, priv_b, dhkey_b);
 
-	if (memcmp(dhkey_a, dhkey, 32))
-		return -EINVAL;
+	if (memcmp(dhkey_a, dhkey, 32)) {
+		ret = -EINVAL;
+		goto out;
+	}
 
 	if (memcmp(dhkey_b, dhkey, 32))
-		return -EINVAL;
+		ret = -EINVAL;
 
-	return 0;
+out:
+	kfree(dhkey_a);
+	return ret;
 }
 
 static char test_ecdh_buffer[32];