From 30e39b7c57422b29533a1bf43f2fd921e088a71d Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Tue, 5 Feb 2013 18:19:13 +0100 Subject: crypto: user - fix info leaks in report API 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 | 22 +++++++++++----------- crypto/pcompress.c | 3 +-- crypto/rng.c | 2 +- crypto/shash.c | 3 ++- 8 files changed, 29 insertions(+), 30 deletions(-) (limited to 'crypto') diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index 8d3a056ebee..45fe4109698 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 e4cb35159be..c706d7415de 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 33bc9b62e9a..0ec05feea43 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 4dd80c72549..0a1ebea3d6f 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 f1ea0a06413..910497bd72b 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)); NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(struct crypto_report_comp), &rcomp); @@ -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)); NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(struct crypto_report_larval), &rl); diff --git a/crypto/pcompress.c b/crypto/pcompress.c index 2e458e5482d..6f2a361bb03 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)); NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(struct crypto_report_comp), &rpcomp); diff --git a/crypto/rng.c b/crypto/rng.c index 64f864fa804..1966c1d0d7f 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 21fc12e2378..3b2a71f6660 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; -- cgit v1.2.3-18-g5258