From 763d9a302ab18da0a0078c9788ed6566d0c974e3 Mon Sep 17 00:00:00 2001 From: Salvatore Benedetto Date: Tue, 25 Apr 2017 16:59:47 +0100 Subject: [PATCH] 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 Signed-off-by: Marcel Holtmann --- net/bluetooth/ecdh_helper.c | 22 ++++++++++++++++------ net/bluetooth/selftest.c | 22 +++++++++++++++++----- 2 files changed, 33 insertions(+), 11 deletions(-) diff --git a/net/bluetooth/ecdh_helper.c b/net/bluetooth/ecdh_helper.c index b6d9aa155485..579684bfc322 100644 --- a/net/bluetooth/ecdh_helper.c +++ b/net/bluetooth/ecdh_helper.c @@ -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); } 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]; -- 2.30.2