Commit 763d9a30 authored by Salvatore Benedetto's avatar Salvatore Benedetto Committed by Marcel Holtmann
Browse files

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: default avatarSalvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 58771c1c

net/bluetooth/ecdh_helper.c

+16 −6
Original line number Diff line number Diff line
@@ -59,16 +59,19 @@ bool compute_ecdh_secret(const u8 public_key[64], const u8 private_key[32], 
	struct ecdh p;

	struct ecdh_completion result;

	struct scatterlist src, dst;

	u8 tmp[64];

	u8 *buf;

	u8 *tmp, *buf;

	unsigned int buf_len;

	int err = -ENOMEM;



	tmp = kmalloc(64, GFP_KERNEL);

	if (!tmp)

		return false;



	tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);

	if (IS_ERR(tfm)) {

		pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",

		       PTR_ERR(tfm));

		return false;

		goto free_tmp;

	}



	req = kpp_request_alloc(tfm, GFP_KERNEL);
@@ -128,6 +131,8 @@ free_req: 
	kpp_request_free(req);

free_kpp:

	crypto_free_kpp(tfm);

free_tmp:

	kfree(tmp);

	return (err == 0);

}
@@ -138,18 +143,21 @@ bool generate_ecdh_keys(u8 public_key[64], u8 private_key[32]) 
	struct ecdh p;

	struct ecdh_completion result;

	struct scatterlist dst;

	u8 tmp[64];

	u8 *buf;

	u8 *tmp, *buf;

	unsigned int buf_len;

	int err = -ENOMEM;

	const unsigned short max_tries = 16;

	unsigned short tries = 0;



	tmp = kmalloc(64, GFP_KERNEL);

	if (!tmp)

		return false;



	tfm = crypto_alloc_kpp("ecdh", CRYPTO_ALG_INTERNAL, 0);

	if (IS_ERR(tfm)) {

		pr_err("alg: kpp: Failed to load tfm for kpp: %ld\n",

		       PTR_ERR(tfm));

		return false;

		goto free_tmp;

	}



	req = kpp_request_alloc(tfm, GFP_KERNEL);
@@ -219,5 +227,7 @@ free_req: 
	kpp_request_free(req);

free_kpp:

	crypto_free_kpp(tfm);

free_tmp:

	kfree(tmp);

	return (err == 0);

}

net/bluetooth/selftest.c

+17 −5
Original line number Diff line number Diff line
@@ -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];

CRA Git | Maintained and supported by SUSTech CRA and CCSE