4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jason A. Donenfeld <ja...@zx2c4.com> commit 329d82309824ff1082dc4a91a5bbed8c3bec1580 upstream. This file is filled with complex cryptography. Thus, the comparisons of MACs and secret keys and curve points and so forth should not add timing attacks, which could either result in a direct forgery, or, given the complexity, some other type of attack. Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com> Signed-off-by: Marcel Holtmann <mar...@holtmann.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- net/bluetooth/smp.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -23,6 +23,7 @@ #include <linux/debugfs.h> #include <linux/scatterlist.h> #include <linux/crypto.h> +#include <crypto/algapi.h> #include <crypto/b128ops.h> #include <crypto/hash.h> @@ -506,7 +507,7 @@ bool smp_irk_matches(struct hci_dev *hde if (err) return false; - return !memcmp(bdaddr->b, hash, 3); + return !crypto_memneq(bdaddr->b, hash, 3); } int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) @@ -559,7 +560,7 @@ int smp_generate_oob(struct hci_dev *hde /* This is unlikely, but we need to check that * we didn't accidentially generate a debug key. */ - if (memcmp(smp->local_sk, debug_sk, 32)) + if (crypto_memneq(smp->local_sk, debug_sk, 32)) break; } smp->debug_key = false; @@ -973,7 +974,7 @@ static u8 smp_random(struct smp_chan *sm if (ret) return SMP_UNSPECIFIED; - if (memcmp(smp->pcnf, confirm, sizeof(smp->pcnf)) != 0) { + if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { BT_ERR("Pairing failed (confirmation values mismatch)"); return SMP_CONFIRM_FAILED; } @@ -1473,7 +1474,7 @@ static u8 sc_passkey_round(struct smp_ch smp->rrnd, r, cfm)) return SMP_UNSPECIFIED; - if (memcmp(smp->pcnf, cfm, 16)) + if (crypto_memneq(smp->pcnf, cfm, 16)) return SMP_CONFIRM_FAILED; smp->passkey_round++; @@ -1857,7 +1858,7 @@ static u8 sc_send_public_key(struct smp_ /* This is unlikely, but we need to check that * we didn't accidentially generate a debug key. */ - if (memcmp(smp->local_sk, debug_sk, 32)) + if (crypto_memneq(smp->local_sk, debug_sk, 32)) break; } } @@ -2122,7 +2123,7 @@ static u8 smp_cmd_pairing_random(struct if (err) return SMP_UNSPECIFIED; - if (memcmp(smp->pcnf, cfm, 16)) + if (crypto_memneq(smp->pcnf, cfm, 16)) return SMP_CONFIRM_FAILED; } else { smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), @@ -2603,7 +2604,7 @@ static int smp_cmd_public_key(struct l2c if (err) return SMP_UNSPECIFIED; - if (memcmp(cfm.confirm_val, smp->pcnf, 16)) + if (crypto_memneq(cfm.confirm_val, smp->pcnf, 16)) return SMP_CONFIRM_FAILED; } @@ -2636,7 +2637,7 @@ static int smp_cmd_public_key(struct l2c else hcon->pending_sec_level = BT_SECURITY_FIPS; - if (!memcmp(debug_pk, smp->remote_pk, 64)) + if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); if (smp->method == DSP_PASSKEY) { @@ -2735,7 +2736,7 @@ static int smp_cmd_dhkey_check(struct l2 if (err) return SMP_UNSPECIFIED; - if (memcmp(check->e, e, 16)) + if (crypto_memneq(check->e, e, 16)) return SMP_DHKEY_CHECK_FAILED; if (!hcon->out) { @@ -3446,7 +3447,7 @@ static int __init test_ah(struct crypto_ if (err) return err; - if (memcmp(res, exp, 3)) + if (crypto_memneq(res, exp, 3)) return -EINVAL; return 0; @@ -3476,7 +3477,7 @@ static int __init test_c1(struct crypto_ if (err) return err; - if (memcmp(res, exp, 16)) + if (crypto_memneq(res, exp, 16)) return -EINVAL; return 0; @@ -3501,7 +3502,7 @@ static int __init test_s1(struct crypto_ if (err) return err; - if (memcmp(res, exp, 16)) + if (crypto_memneq(res, exp, 16)) return -EINVAL; return 0; @@ -3533,7 +3534,7 @@ static int __init test_f4(struct crypto_ if (err) return err; - if (memcmp(res, exp, 16)) + if (crypto_memneq(res, exp, 16)) return -EINVAL; return 0; @@ -3567,10 +3568,10 @@ static int __init test_f5(struct crypto_ if (err) return err; - if (memcmp(mackey, exp_mackey, 16)) + if (crypto_memneq(mackey, exp_mackey, 16)) return -EINVAL; - if (memcmp(ltk, exp_ltk, 16)) + if (crypto_memneq(ltk, exp_ltk, 16)) return -EINVAL; return 0; @@ -3603,7 +3604,7 @@ static int __init test_f6(struct crypto_ if (err) return err; - if (memcmp(res, exp, 16)) + if (crypto_memneq(res, exp, 16)) return -EINVAL; return 0; @@ -3657,7 +3658,7 @@ static int __init test_h6(struct crypto_ if (err) return err; - if (memcmp(res, exp, 16)) + if (crypto_memneq(res, exp, 16)) return -EINVAL; return 0;