Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933775Ab3CLWkZ (ORCPT ); Tue, 12 Mar 2013 18:40:25 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60392 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755329Ab3CLWdb (ORCPT ); Tue, 12 Mar 2013 18:33:31 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mathias Krause , Steffen Klassert , Herbert Xu Subject: [ 081/100] crypto: user - fix info leaks in report API Date: Tue, 12 Mar 2013 15:32:06 -0700 Message-Id: <20130312223131.667458236@linuxfoundation.org> X-Mailer: git-send-email 1.8.1.rc1.5.g7e0651a In-Reply-To: <20130312223122.884099393@linuxfoundation.org> References: <20130312223122.884099393@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7963 Lines: 215 3.8-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: Greg Kroah-Hartman --- crypto/ablkcipher.c | 12 ++++++------ crypto/aead.c | 9 ++++----- crypto/ahash.c | 2 +- crypto/blkcipher.c | 6 +++--- crypto/crypto_user.c | 20 ++++++++++---------- crypto/pcompress.c | 3 +-- crypto/rng.c | 2 +- crypto/shash.c | 3 ++- 8 files changed, 28 insertions(+), 29 deletions(-) --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -388,9 +388,9 @@ static int crypto_ablkcipher_report(stru { 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(struc { 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; --- a/crypto/aead.c +++ b/crypto/aead.c @@ -117,9 +117,8 @@ static int crypto_aead_report(struct sk_ 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 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; --- a/crypto/ahash.c +++ b/crypto/ahash.c @@ -404,7 +404,7 @@ static int crypto_ahash_report(struct sk { 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; --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -499,9 +499,9 @@ static int crypto_blkcipher_report(struc { 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; --- a/crypto/crypto_user.c +++ b/crypto/crypto_user.c @@ -75,7 +75,7 @@ static int crypto_report_cipher(struct s { 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_ { 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 cryp 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; --- a/crypto/pcompress.c +++ b/crypto/pcompress.c @@ -53,8 +53,7 @@ static int crypto_pcomp_report(struct sk { 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; --- a/crypto/rng.c +++ b/crypto/rng.c @@ -65,7 +65,7 @@ static int crypto_rng_report(struct sk_b { 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; --- a/crypto/shash.c +++ b/crypto/shash.c @@ -530,7 +530,8 @@ static int crypto_shash_report(struct sk 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/