From a62b01cd6cc1feb5e80d64d6937c291473ed82cb Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 20 Sep 2013 09:55:40 +0200 Subject: crypto: create generic version of ablk_helper Create a generic version of ablk_helper so it can be reused by other architectures. Acked-by: Jussi Kivilinna Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- include/crypto/ablk_helper.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 include/crypto/ablk_helper.h (limited to 'include/crypto') diff --git a/include/crypto/ablk_helper.h b/include/crypto/ablk_helper.h new file mode 100644 index 00000000000..4f93df50c23 --- /dev/null +++ b/include/crypto/ablk_helper.h @@ -0,0 +1,31 @@ +/* + * Shared async block cipher helpers + */ + +#ifndef _CRYPTO_ABLK_HELPER_H +#define _CRYPTO_ABLK_HELPER_H + +#include +#include +#include + +struct async_helper_ctx { + struct cryptd_ablkcipher *cryptd_tfm; +}; + +extern int ablk_set_key(struct crypto_ablkcipher *tfm, const u8 *key, + unsigned int key_len); + +extern int __ablk_encrypt(struct ablkcipher_request *req); + +extern int ablk_encrypt(struct ablkcipher_request *req); + +extern int ablk_decrypt(struct ablkcipher_request *req); + +extern void ablk_exit(struct crypto_tfm *tfm); + +extern int ablk_init_common(struct crypto_tfm *tfm, const char *drv_name); + +extern int ablk_init(struct crypto_tfm *tfm); + +#endif /* _CRYPTO_ABLK_HELPER_H */ -- cgit v1.2.3-70-g09d2 From 6bf37e5aa90f18baf5acf4874bca505dd667c37f Mon Sep 17 00:00:00 2001 From: James Yonan Date: Thu, 26 Sep 2013 02:20:39 -0600 Subject: crypto: crypto_memneq - add equality testing of memory regions w/o timing leaks When comparing MAC hashes, AEAD authentication tags, or other hash values in the context of authentication or integrity checking, it is important not to leak timing information to a potential attacker, i.e. when communication happens over a network. Bytewise memory comparisons (such as memcmp) are usually optimized so that they return a nonzero value as soon as a mismatch is found. E.g, on x86_64/i5 for 512 bytes this can be ~50 cyc for a full mismatch and up to ~850 cyc for a full match (cold). This early-return behavior can leak timing information as a side channel, allowing an attacker to iteratively guess the correct result. This patch adds a new method crypto_memneq ("memory not equal to each other") to the crypto API that compares memory areas of the same length in roughly "constant time" (cache misses could change the timing, but since they don't reveal information about the content of the strings being compared, they are effectively benign). Iow, best and worst case behaviour take the same amount of time to complete (in contrast to memcmp). Note that crypto_memneq (unlike memcmp) can only be used to test for equality or inequality, NOT for lexicographical order. This, however, is not an issue for its use-cases within the crypto API. We tried to locate all of the places in the crypto API where memcmp was being used for authentication or integrity checking, and convert them over to crypto_memneq. crypto_memneq is declared noinline, placed in its own source file, and compiled with optimizations that might increase code size disabled ("Os") because a smart compiler (or LTO) might notice that the return value is always compared against zero/nonzero, and might then reintroduce the same early-return optimization that we are trying to avoid. Using #pragma or __attribute__ optimization annotations of the code for disabling optimization was avoided as it seems to be considered broken or unmaintained for long time in GCC [1]. Therefore, we work around that by specifying the compile flag for memneq.o directly in the Makefile. We found that this seems to be most appropriate. As we use ("Os"), this patch also provides a loop-free "fast-path" for frequently used 16 byte digests. Similarly to kernel library string functions, leave an option for future even further optimized architecture specific assembler implementations. This was a joint work of James Yonan and Daniel Borkmann. Also thanks for feedback from Florian Weimer on this and earlier proposals [2]. [1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html [2] https://lkml.org/lkml/2013/2/10/131 Signed-off-by: James Yonan Signed-off-by: Daniel Borkmann Cc: Florian Weimer Signed-off-by: Herbert Xu --- crypto/Makefile | 7 ++- crypto/asymmetric_keys/rsa.c | 5 +- crypto/authenc.c | 6 +- crypto/authencesn.c | 8 +-- crypto/ccm.c | 4 +- crypto/gcm.c | 2 +- crypto/memneq.c | 138 +++++++++++++++++++++++++++++++++++++++++++ include/crypto/algapi.h | 18 +++++- 8 files changed, 174 insertions(+), 14 deletions(-) create mode 100644 crypto/memneq.c (limited to 'include/crypto') diff --git a/crypto/Makefile b/crypto/Makefile index 580af977f49..d6a401c58d1 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -2,8 +2,13 @@ # Cryptographic API # +# memneq MUST be built with -Os or -O0 to prevent early-return optimizations +# that will defeat memneq's actual purpose to prevent timing attacks. +CFLAGS_REMOVE_memneq.o := -O1 -O2 -O3 +CFLAGS_memneq.o := -Os + obj-$(CONFIG_CRYPTO) += crypto.o -crypto-y := api.o cipher.o compress.o +crypto-y := api.o cipher.o compress.o memneq.o obj-$(CONFIG_CRYPTO_WORKQUEUE) += crypto_wq.o diff --git a/crypto/asymmetric_keys/rsa.c b/crypto/asymmetric_keys/rsa.c index 4a6a0696f8a..1912b9be504 100644 --- a/crypto/asymmetric_keys/rsa.c +++ b/crypto/asymmetric_keys/rsa.c @@ -13,6 +13,7 @@ #include #include #include +#include #include "public_key.h" MODULE_LICENSE("GPL"); @@ -189,12 +190,12 @@ static int RSA_verify(const u8 *H, const u8 *EM, size_t k, size_t hash_size, } } - if (memcmp(asn1_template, EM + T_offset, asn1_size) != 0) { + if (crypto_memneq(asn1_template, EM + T_offset, asn1_size) != 0) { kleave(" = -EBADMSG [EM[T] ASN.1 mismatch]"); return -EBADMSG; } - if (memcmp(H, EM + T_offset + asn1_size, hash_size) != 0) { + if (crypto_memneq(H, EM + T_offset + asn1_size, hash_size) != 0) { kleave(" = -EKEYREJECTED [EM[T] hash mismatch]"); return -EKEYREJECTED; } diff --git a/crypto/authenc.c b/crypto/authenc.c index ffce19de05c..2b3f4abda92 100644 --- a/crypto/authenc.c +++ b/crypto/authenc.c @@ -188,7 +188,7 @@ static void authenc_verify_ahash_update_done(struct crypto_async_request *areq, scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0; + err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0; if (err) goto out; @@ -227,7 +227,7 @@ static void authenc_verify_ahash_done(struct crypto_async_request *areq, scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0; + err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0; if (err) goto out; @@ -462,7 +462,7 @@ static int crypto_authenc_verify(struct aead_request *req, ihash = ohash + authsize; scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0; + return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0; } static int crypto_authenc_iverify(struct aead_request *req, u8 *iv, diff --git a/crypto/authencesn.c b/crypto/authencesn.c index ab53762fc30..c569d58de66 100644 --- a/crypto/authencesn.c +++ b/crypto/authencesn.c @@ -247,7 +247,7 @@ static void authenc_esn_verify_ahash_update_done(struct crypto_async_request *ar scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0; + err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0; if (err) goto out; @@ -296,7 +296,7 @@ static void authenc_esn_verify_ahash_update_done2(struct crypto_async_request *a scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0; + err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0; if (err) goto out; @@ -336,7 +336,7 @@ static void authenc_esn_verify_ahash_done(struct crypto_async_request *areq, scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - err = memcmp(ihash, ahreq->result, authsize) ? -EBADMSG : 0; + err = crypto_memneq(ihash, ahreq->result, authsize) ? -EBADMSG : 0; if (err) goto out; @@ -568,7 +568,7 @@ static int crypto_authenc_esn_verify(struct aead_request *req) ihash = ohash + authsize; scatterwalk_map_and_copy(ihash, areq_ctx->sg, areq_ctx->cryptlen, authsize, 0); - return memcmp(ihash, ohash, authsize) ? -EBADMSG : 0; + return crypto_memneq(ihash, ohash, authsize) ? -EBADMSG : 0; } static int crypto_authenc_esn_iverify(struct aead_request *req, u8 *iv, diff --git a/crypto/ccm.c b/crypto/ccm.c index 499c91717d9..3e05499d183 100644 --- a/crypto/ccm.c +++ b/crypto/ccm.c @@ -363,7 +363,7 @@ static void crypto_ccm_decrypt_done(struct crypto_async_request *areq, if (!err) { err = crypto_ccm_auth(req, req->dst, cryptlen); - if (!err && memcmp(pctx->auth_tag, pctx->odata, authsize)) + if (!err && crypto_memneq(pctx->auth_tag, pctx->odata, authsize)) err = -EBADMSG; } aead_request_complete(req, err); @@ -422,7 +422,7 @@ static int crypto_ccm_decrypt(struct aead_request *req) return err; /* verify */ - if (memcmp(authtag, odata, authsize)) + if (crypto_memneq(authtag, odata, authsize)) return -EBADMSG; return err; diff --git a/crypto/gcm.c b/crypto/gcm.c index 43e1fb05ea5..b4f01793900 100644 --- a/crypto/gcm.c +++ b/crypto/gcm.c @@ -582,7 +582,7 @@ static int crypto_gcm_verify(struct aead_request *req, crypto_xor(auth_tag, iauth_tag, 16); scatterwalk_map_and_copy(iauth_tag, req->src, cryptlen, authsize, 0); - return memcmp(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; + return crypto_memneq(iauth_tag, auth_tag, authsize) ? -EBADMSG : 0; } static void gcm_decrypt_done(struct crypto_async_request *areq, int err) diff --git a/crypto/memneq.c b/crypto/memneq.c new file mode 100644 index 00000000000..cd0162221c1 --- /dev/null +++ b/crypto/memneq.c @@ -0,0 +1,138 @@ +/* + * Constant-time equality testing of memory regions. + * + * Authors: + * + * James Yonan + * Daniel Borkmann + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2013 OpenVPN Technologies, Inc. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * The full GNU General Public License is included in this distribution + * in the file called LICENSE.GPL. + * + * BSD LICENSE + * + * Copyright(c) 2013 OpenVPN Technologies, Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of OpenVPN Technologies nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include + +#ifndef __HAVE_ARCH_CRYPTO_MEMNEQ + +/* Generic path for arbitrary size */ +static inline unsigned long +__crypto_memneq_generic(const void *a, const void *b, size_t size) +{ + unsigned long neq = 0; + +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) + while (size >= sizeof(unsigned long)) { + neq |= *(unsigned long *)a ^ *(unsigned long *)b; + a += sizeof(unsigned long); + b += sizeof(unsigned long); + size -= sizeof(unsigned long); + } +#endif /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */ + while (size > 0) { + neq |= *(unsigned char *)a ^ *(unsigned char *)b; + a += 1; + b += 1; + size -= 1; + } + return neq; +} + +/* Loop-free fast-path for frequently used 16-byte size */ +static inline unsigned long __crypto_memneq_16(const void *a, const void *b) +{ +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS + if (sizeof(unsigned long) == 8) + return ((*(unsigned long *)(a) ^ *(unsigned long *)(b)) + | (*(unsigned long *)(a+8) ^ *(unsigned long *)(b+8))); + else if (sizeof(unsigned int) == 4) + return ((*(unsigned int *)(a) ^ *(unsigned int *)(b)) + | (*(unsigned int *)(a+4) ^ *(unsigned int *)(b+4)) + | (*(unsigned int *)(a+8) ^ *(unsigned int *)(b+8)) + | (*(unsigned int *)(a+12) ^ *(unsigned int *)(b+12))); + else +#endif /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */ + return ((*(unsigned char *)(a) ^ *(unsigned char *)(b)) + | (*(unsigned char *)(a+1) ^ *(unsigned char *)(b+1)) + | (*(unsigned char *)(a+2) ^ *(unsigned char *)(b+2)) + | (*(unsigned char *)(a+3) ^ *(unsigned char *)(b+3)) + | (*(unsigned char *)(a+4) ^ *(unsigned char *)(b+4)) + | (*(unsigned char *)(a+5) ^ *(unsigned char *)(b+5)) + | (*(unsigned char *)(a+6) ^ *(unsigned char *)(b+6)) + | (*(unsigned char *)(a+7) ^ *(unsigned char *)(b+7)) + | (*(unsigned char *)(a+8) ^ *(unsigned char *)(b+8)) + | (*(unsigned char *)(a+9) ^ *(unsigned char *)(b+9)) + | (*(unsigned char *)(a+10) ^ *(unsigned char *)(b+10)) + | (*(unsigned char *)(a+11) ^ *(unsigned char *)(b+11)) + | (*(unsigned char *)(a+12) ^ *(unsigned char *)(b+12)) + | (*(unsigned char *)(a+13) ^ *(unsigned char *)(b+13)) + | (*(unsigned char *)(a+14) ^ *(unsigned char *)(b+14)) + | (*(unsigned char *)(a+15) ^ *(unsigned char *)(b+15))); +} + +/* Compare two areas of memory without leaking timing information, + * and with special optimizations for common sizes. Users should + * not call this function directly, but should instead use + * crypto_memneq defined in crypto/algapi.h. + */ +noinline unsigned long __crypto_memneq(const void *a, const void *b, + size_t size) +{ + switch (size) { + case 16: + return __crypto_memneq_16(a, b); + default: + return __crypto_memneq_generic(a, b, size); + } +} +EXPORT_SYMBOL(__crypto_memneq); + +#endif /* __HAVE_ARCH_CRYPTO_MEMNEQ */ diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h index 418d270e180..e73c19e90e3 100644 --- a/include/crypto/algapi.h +++ b/include/crypto/algapi.h @@ -386,5 +386,21 @@ static inline int crypto_requires_sync(u32 type, u32 mask) return (type ^ CRYPTO_ALG_ASYNC) & mask & CRYPTO_ALG_ASYNC; } -#endif /* _CRYPTO_ALGAPI_H */ +noinline unsigned long __crypto_memneq(const void *a, const void *b, size_t size); + +/** + * crypto_memneq - Compare two areas of memory without leaking + * timing information. + * + * @a: One area of memory + * @b: Another area of memory + * @size: The size of the area. + * + * Returns 0 when data is equal, 1 otherwise. + */ +static inline int crypto_memneq(const void *a, const void *b, size_t size) +{ + return __crypto_memneq(a, b, size) != 0UL ? 1 : 0; +} +#endif /* _CRYPTO_ALGAPI_H */ -- cgit v1.2.3-70-g09d2 From bc6e2bdb71056607141ada309a185f0a50b1aeaf Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Tue, 15 Oct 2013 13:49:30 +0200 Subject: crypto: authenc - Export key parsing helper function AEAD key parsing is duplicated to multiple places in the kernel. Add a common helper function to consolidate that functionality. Cc: Herbert Xu Cc: "David S. Miller" Signed-off-by: Mathias Krause Signed-off-by: Herbert Xu --- crypto/authenc.c | 48 ++++++++++++++++++++++++++++++------------------ include/crypto/authenc.h | 12 +++++++++++- 2 files changed, 41 insertions(+), 19 deletions(-) (limited to 'include/crypto') diff --git a/crypto/authenc.c b/crypto/authenc.c index 2b3f4abda92..1875e7026e8 100644 --- a/crypto/authenc.c +++ b/crypto/authenc.c @@ -52,40 +52,52 @@ static void authenc_request_complete(struct aead_request *req, int err) aead_request_complete(req, err); } -static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, - unsigned int keylen) +int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key, + unsigned int keylen) { - unsigned int authkeylen; - unsigned int enckeylen; - struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); - struct crypto_ahash *auth = ctx->auth; - struct crypto_ablkcipher *enc = ctx->enc; - struct rtattr *rta = (void *)key; + struct rtattr *rta = (struct rtattr *)key; struct crypto_authenc_key_param *param; - int err = -EINVAL; if (!RTA_OK(rta, keylen)) - goto badkey; + return -EINVAL; if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM) - goto badkey; + return -EINVAL; if (RTA_PAYLOAD(rta) < sizeof(*param)) - goto badkey; + return -EINVAL; param = RTA_DATA(rta); - enckeylen = be32_to_cpu(param->enckeylen); + keys->enckeylen = be32_to_cpu(param->enckeylen); key += RTA_ALIGN(rta->rta_len); keylen -= RTA_ALIGN(rta->rta_len); - if (keylen < enckeylen) - goto badkey; + if (keylen < keys->enckeylen) + return -EINVAL; - authkeylen = keylen - enckeylen; + keys->authkeylen = keylen - keys->enckeylen; + keys->authkey = key; + keys->enckey = key + keys->authkeylen; + + return 0; +} +EXPORT_SYMBOL_GPL(crypto_authenc_extractkeys); + +static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, + unsigned int keylen) +{ + struct crypto_authenc_ctx *ctx = crypto_aead_ctx(authenc); + struct crypto_ahash *auth = ctx->auth; + struct crypto_ablkcipher *enc = ctx->enc; + struct crypto_authenc_keys keys; + int err = -EINVAL; + + if (crypto_authenc_extractkeys(&keys, key, keylen) != 0) + goto badkey; crypto_ahash_clear_flags(auth, CRYPTO_TFM_REQ_MASK); crypto_ahash_set_flags(auth, crypto_aead_get_flags(authenc) & CRYPTO_TFM_REQ_MASK); - err = crypto_ahash_setkey(auth, key, authkeylen); + err = crypto_ahash_setkey(auth, keys.authkey, keys.authkeylen); crypto_aead_set_flags(authenc, crypto_ahash_get_flags(auth) & CRYPTO_TFM_RES_MASK); @@ -95,7 +107,7 @@ static int crypto_authenc_setkey(struct crypto_aead *authenc, const u8 *key, crypto_ablkcipher_clear_flags(enc, CRYPTO_TFM_REQ_MASK); crypto_ablkcipher_set_flags(enc, crypto_aead_get_flags(authenc) & CRYPTO_TFM_REQ_MASK); - err = crypto_ablkcipher_setkey(enc, key + authkeylen, enckeylen); + err = crypto_ablkcipher_setkey(enc, keys.enckey, keys.enckeylen); crypto_aead_set_flags(authenc, crypto_ablkcipher_get_flags(enc) & CRYPTO_TFM_RES_MASK); diff --git a/include/crypto/authenc.h b/include/crypto/authenc.h index e47b044929a..6775059539b 100644 --- a/include/crypto/authenc.h +++ b/include/crypto/authenc.h @@ -23,5 +23,15 @@ struct crypto_authenc_key_param { __be32 enckeylen; }; -#endif /* _CRYPTO_AUTHENC_H */ +struct crypto_authenc_keys { + const u8 *authkey; + const u8 *enckey; + + unsigned int authkeylen; + unsigned int enckeylen; +}; +int crypto_authenc_extractkeys(struct crypto_authenc_keys *keys, const u8 *key, + unsigned int keylen); + +#endif /* _CRYPTO_AUTHENC_H */ -- cgit v1.2.3-70-g09d2 From 41da8b5adba77e22584f8b45f9641504fa885308 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Tue, 12 Nov 2013 11:46:10 -0600 Subject: crypto: scatterwalk - Set the chain pointer indication bit The scatterwalk_crypto_chain function invokes the scatterwalk_sg_chain function to chain two scatterlists, but the chain pointer indication bit is not set. When the resulting scatterlist is used, for example, by sg_nents to count the number of scatterlist entries, a segfault occurs because sg_nents does not follow the chain pointer to the chained scatterlist. Update scatterwalk_sg_chain to set the chain pointer indication bit as is done by the sg_chain function. Cc: stable@vger.kernel.org Signed-off-by: Tom Lendacky Signed-off-by: Herbert Xu --- include/crypto/scatterwalk.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/crypto') diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 13621cc8cf4..64ebede184f 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -36,6 +36,7 @@ static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num, { sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0); sg1[num - 1].page_link &= ~0x02; + sg1[num - 1].page_link |= 0x01; } static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg) -- cgit v1.2.3-70-g09d2 From 389a5390583a18e45bc4abd4439291abec5e7a63 Mon Sep 17 00:00:00 2001 From: Tom Lendacky Date: Thu, 5 Dec 2013 13:09:53 -0600 Subject: crypto: scatterwalk - Use sg_chain_ptr on chain entries Now that scatterwalk_sg_chain sets the chain pointer bit the sg_page call in scatterwalk_sg_next hits a BUG_ON when CONFIG_DEBUG_SG is enabled. Use sg_chain_ptr instead of sg_page on a chain entry. Cc: stable@vger.kernel.org Signed-off-by: Tom Lendacky Signed-off-by: Herbert Xu --- include/crypto/scatterwalk.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/crypto') diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 64ebede184f..6a626a507b8 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -44,7 +44,7 @@ static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg) if (sg_is_last(sg)) return NULL; - return (++sg)->length ? sg : (void *)sg_page(sg); + return (++sg)->length ? sg : sg_chain_ptr(sg); } static inline void scatterwalk_crypto_chain(struct scatterlist *head, -- cgit v1.2.3-70-g09d2