Hi,
On Tuesday, 25 April 2017 08:59:47 PDT Salvatore Benedetto wrote:
> 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@xxxxxxxxx>
> ---
> net/bluetooth/ecdh_helper.c | 6 ++++--
> net/bluetooth/selftest.c | 16 +++++++++++-----
> 2 files changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/net/bluetooth/ecdh_helper.c b/net/bluetooth/ecdh_helper.c
> index b6d9aa1..8018447 100644
> --- a/net/bluetooth/ecdh_helper.c
> +++ b/net/bluetooth/ecdh_helper.c
> @@ -59,7 +59,7 @@ 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 *tmp = kmalloc(64, GFP_KERNEL);
Should this be checked for null?
> u8 *buf;
> unsigned int buf_len;
> int err = -ENOMEM;
> @@ -68,7 +68,7 @@ bool compute_ecdh_secret(const u8 public_key[64], const u8
> private_key[32], 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 +128,8 @@ bool compute_ecdh_secret(const u8 public_key[64], const
> u8 private_key[32], 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 efef281..9a72f8f 100644
> --- a/net/bluetooth/selftest.c
> +++ b/net/bluetooth/selftest.c
> @@ -142,18 +142,24 @@ 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 *dhkey_a = kmalloc(64, GFP_KERNEL);
> + u8 *dhkey_b = &dhkey_a[32];
> + int ret = 0;
>
> 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];
--
pozdrawiam
Szymon Janc
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