From patchwork Thu Mar 14 10:36:14 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 227619 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 28C132C00A6 for ; Thu, 14 Mar 2013 21:43:13 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UG5co-0000QR-OE; Thu, 14 Mar 2013 10:43:06 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UG5YA-0006Tq-AR for kernel-team@lists.ubuntu.com; Thu, 14 Mar 2013 10:38:18 +0000 Received: from bl15-242-192.dsl.telepac.pt ([188.80.242.192] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UG5Y9-0003rj-O8; Thu, 14 Mar 2013 10:38:18 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 81/88] crypto: user - fix info leaks in report API Date: Thu, 14 Mar 2013 10:36:14 +0000 Message-Id: <1363257381-15900-82-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1363257381-15900-1-git-send-email-luis.henriques@canonical.com> References: <1363257381-15900-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Cc: Steffen Klassert , Mathias Krause , Herbert Xu X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.5.7.8 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Mathias Krause commit 9a5467bf7b6e9e02ec9c3da4e23747c05faeaac6 upstream. Three errors resulting in kernel memory disclosure: 1/ The structures used for the netlink based crypto algorithm report API are located on the stack. As snprintf() does not fill the remainder of the buffer with null bytes, those stack bytes will be disclosed to users of the API. Switch to strncpy() to fix this. 2/ crypto_report_one() does not initialize all field of struct crypto_user_alg. Fix this to fix the heap info leak. 3/ For the module name we should copy only as many bytes as module_name() returns -- not as much as the destination buffer could hold. But the current code does not and therefore copies random data from behind the end of the module name, as the module name is always shorter than CRYPTO_MAX_ALG_NAME. Also switch to use strncpy() to copy the algorithm's name and driver_name. They are strings, after all. Signed-off-by: Mathias Krause Cc: Steffen Klassert Signed-off-by: Herbert Xu Signed-off-by: Luis Henriques --- crypto/ablkcipher.c | 12 ++++++------ crypto/aead.c | 9 ++++----- crypto/ahash.c | 2 +- crypto/blkcipher.c | 6 +++--- crypto/crypto_user.c | 22 +++++++++++----------- crypto/pcompress.c | 3 +-- crypto/rng.c | 2 +- crypto/shash.c | 3 ++- 8 files changed, 29 insertions(+), 30 deletions(-) diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index 533de95..7d4a8d2 100644 --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -388,9 +388,9 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_blkcipher rblkcipher; - snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "ablkcipher"); - snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s", - alg->cra_ablkcipher.geniv ?: ""); + strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type)); + strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "", + sizeof(rblkcipher.geniv)); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; @@ -469,9 +469,9 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_blkcipher rblkcipher; - snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "givcipher"); - snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s", - alg->cra_ablkcipher.geniv ?: ""); + strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type)); + strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "", + sizeof(rblkcipher.geniv)); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; diff --git a/crypto/aead.c b/crypto/aead.c index 0b8121e..27bc487 100644 --- a/crypto/aead.c +++ b/crypto/aead.c @@ -117,9 +117,8 @@ static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg) struct crypto_report_aead raead; struct aead_alg *aead = &alg->cra_aead; - snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "aead"); - snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s", - aead->geniv ?: ""); + strncpy(raead.type, "aead", sizeof(raead.type)); + strncpy(raead.geniv, aead->geniv ?: "", sizeof(raead.geniv)); raead.blocksize = alg->cra_blocksize; raead.maxauthsize = aead->maxauthsize; @@ -203,8 +202,8 @@ static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg) struct crypto_report_aead raead; struct aead_alg *aead = &alg->cra_aead; - snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "nivaead"); - snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s", aead->geniv); + strncpy(raead.type, "nivaead", sizeof(raead.type)); + strncpy(raead.geniv, aead->geniv, sizeof(raead.geniv)); raead.blocksize = alg->cra_blocksize; raead.maxauthsize = aead->maxauthsize; diff --git a/crypto/ahash.c b/crypto/ahash.c index 3887856..793a27f 100644 --- a/crypto/ahash.c +++ b/crypto/ahash.c @@ -404,7 +404,7 @@ static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_hash rhash; - snprintf(rhash.type, CRYPTO_MAX_ALG_NAME, "%s", "ahash"); + strncpy(rhash.type, "ahash", sizeof(rhash.type)); rhash.blocksize = alg->cra_blocksize; rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize; diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index a8d85a1..c44e014 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -499,9 +499,9 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_blkcipher rblkcipher; - snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "blkcipher"); - snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s", - alg->cra_blkcipher.geniv ?: ""); + strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type)); + strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "", + sizeof(rblkcipher.geniv)); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize; diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c index 5a37ead..ee69458 100644 --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -75,7 +75,7 @@ static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_cipher rcipher; - snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher"); + strncpy(rcipher.type, "cipher", sizeof(rcipher.type)); rcipher.blocksize = alg->cra_blocksize; rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; @@ -94,8 +94,7 @@ static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_comp rcomp; - snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression"); - + strncpy(rcomp.type, "compression", sizeof(rcomp.type)); if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(struct crypto_report_comp), &rcomp)) goto nla_put_failure; @@ -108,12 +107,14 @@ nla_put_failure: static int crypto_report_one(struct crypto_alg *alg, struct crypto_user_alg *ualg, struct sk_buff *skb) { - memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name)); - memcpy(&ualg->cru_driver_name, &alg->cra_driver_name, - sizeof(ualg->cru_driver_name)); - memcpy(&ualg->cru_module_name, module_name(alg->cra_module), - CRYPTO_MAX_ALG_NAME); - + strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); + strncpy(ualg->cru_driver_name, alg->cra_driver_name, + sizeof(ualg->cru_driver_name)); + strncpy(ualg->cru_module_name, module_name(alg->cra_module), + sizeof(ualg->cru_module_name)); + + ualg->cru_type = 0; + ualg->cru_mask = 0; ualg->cru_flags = alg->cra_flags; ualg->cru_refcnt = atomic_read(&alg->cra_refcnt); @@ -122,8 +123,7 @@ static int crypto_report_one(struct crypto_alg *alg, if (alg->cra_flags & CRYPTO_ALG_LARVAL) { struct crypto_report_larval rl; - snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval"); - + strncpy(rl.type, "larval", sizeof(rl.type)); if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(struct crypto_report_larval), &rl)) goto nla_put_failure; diff --git a/crypto/pcompress.c b/crypto/pcompress.c index 04e083f..7140fe7 100644 --- a/crypto/pcompress.c +++ b/crypto/pcompress.c @@ -53,8 +53,7 @@ static int crypto_pcomp_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_comp rpcomp; - snprintf(rpcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "pcomp"); - + strncpy(rpcomp.type, "pcomp", sizeof(rpcomp.type)); if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(struct crypto_report_comp), &rpcomp)) goto nla_put_failure; diff --git a/crypto/rng.c b/crypto/rng.c index f3b7894..e0a25c2 100644 --- a/crypto/rng.c +++ b/crypto/rng.c @@ -65,7 +65,7 @@ static int crypto_rng_report(struct sk_buff *skb, struct crypto_alg *alg) { struct crypto_report_rng rrng; - snprintf(rrng.type, CRYPTO_MAX_ALG_NAME, "%s", "rng"); + strncpy(rrng.type, "rng", sizeof(rrng.type)); rrng.seedsize = alg->cra_rng.seedsize; diff --git a/crypto/shash.c b/crypto/shash.c index 32067f4..18e4b00 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -530,7 +530,8 @@ static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg) struct crypto_report_hash rhash; struct shash_alg *salg = __crypto_shash_alg(alg); - snprintf(rhash.type, CRYPTO_MAX_ALG_NAME, "%s", "shash"); + strncpy(rhash.type, "shash", sizeof(rhash.type)); + rhash.blocksize = alg->cra_blocksize; rhash.digestsize = salg->digestsize;