From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:46960 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730910AbeLKP5w (ORCPT ); Tue, 11 Dec 2018 10:57:52 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pan Bian , Herbert Xu Subject: [PATCH 4.19 096/118] crypto: do not free algorithm before using Date: Tue, 11 Dec 2018 16:41:55 +0100 Message-Id: <20181211151648.142392381@linuxfoundation.org> In-Reply-To: <20181211151644.216668863@linuxfoundation.org> References: <20181211151644.216668863@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pan Bian commit e5bde04ccce64d808f8b00a489a1fe5825d285cb upstream. In multiple functions, the algorithm fields are read after its reference is dropped through crypto_mod_put. In this case, the algorithm memory may be freed, resulting in use-after-free bugs. This patch delays the put operation until the algorithm is never used. Fixes: 79c65d179a40 ("crypto: cbc - Convert to skcipher") Fixes: a7d85e06ed80 ("crypto: cfb - add support for Cipher FeedBack mode") Fixes: 043a44001b9e ("crypto: pcbc - Convert to skcipher") Cc: Signed-off-by: Pan Bian Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/cbc.c | 6 ++++-- crypto/cfb.c | 6 ++++-- crypto/pcbc.c | 6 ++++-- 3 files changed, 12 insertions(+), 6 deletions(-) --- a/crypto/cbc.c +++ b/crypto/cbc.c @@ -140,9 +140,8 @@ static int crypto_cbc_create(struct cryp spawn = skcipher_instance_ctx(inst); err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst), CRYPTO_ALG_TYPE_MASK); - crypto_mod_put(alg); if (err) - goto err_free_inst; + goto err_put_alg; err = crypto_inst_setname(skcipher_crypto_instance(inst), "cbc", alg); if (err) @@ -174,12 +173,15 @@ static int crypto_cbc_create(struct cryp err = skcipher_register_instance(tmpl, inst); if (err) goto err_drop_spawn; + crypto_mod_put(alg); out: return err; err_drop_spawn: crypto_drop_spawn(spawn); +err_put_alg: + crypto_mod_put(alg); err_free_inst: kfree(inst); goto out; --- a/crypto/cfb.c +++ b/crypto/cfb.c @@ -286,9 +286,8 @@ static int crypto_cfb_create(struct cryp spawn = skcipher_instance_ctx(inst); err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst), CRYPTO_ALG_TYPE_MASK); - crypto_mod_put(alg); if (err) - goto err_free_inst; + goto err_put_alg; err = crypto_inst_setname(skcipher_crypto_instance(inst), "cfb", alg); if (err) @@ -317,12 +316,15 @@ static int crypto_cfb_create(struct cryp err = skcipher_register_instance(tmpl, inst); if (err) goto err_drop_spawn; + crypto_mod_put(alg); out: return err; err_drop_spawn: crypto_drop_spawn(spawn); +err_put_alg: + crypto_mod_put(alg); err_free_inst: kfree(inst); goto out; --- a/crypto/pcbc.c +++ b/crypto/pcbc.c @@ -244,9 +244,8 @@ static int crypto_pcbc_create(struct cry spawn = skcipher_instance_ctx(inst); err = crypto_init_spawn(spawn, alg, skcipher_crypto_instance(inst), CRYPTO_ALG_TYPE_MASK); - crypto_mod_put(alg); if (err) - goto err_free_inst; + goto err_put_alg; err = crypto_inst_setname(skcipher_crypto_instance(inst), "pcbc", alg); if (err) @@ -275,12 +274,15 @@ static int crypto_pcbc_create(struct cry err = skcipher_register_instance(tmpl, inst); if (err) goto err_drop_spawn; + crypto_mod_put(alg); out: return err; err_drop_spawn: crypto_drop_spawn(spawn); +err_put_alg: + crypto_mod_put(alg); err_free_inst: kfree(inst); goto out;