From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 447A2CCA493 for ; Thu, 23 Jun 2022 16:47:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232711AbiFWQrH (ORCPT ); Thu, 23 Jun 2022 12:47:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47686 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232565AbiFWQqh (ORCPT ); Thu, 23 Jun 2022 12:46:37 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68E7249B53; Thu, 23 Jun 2022 09:46:32 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 13BCBB82490; Thu, 23 Jun 2022 16:46:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6F55FC3411B; Thu, 23 Jun 2022 16:46:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656002789; bh=jowfPDK8woZaDFsJMGdUuGhq2AgGDxQotjFEH04bCi8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wf6iAYu7JrrXEQu5H+Ce1Aljhi7d/XSPfuPxOYfVuNpkQx4eQVZQPBDa1FdiUEnaD smI1oUvWDOzq6jHue4J563Y2D0vMreTvz6GyUASE2xRVF0xxca0BNvG2lTYyH2733h YK8n/W7drjtzOFAYYd454F1Di09ftCRIXg7IcCdQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Biggers , Herbert Xu , "Jason A. Donenfeld" Subject: [PATCH 4.9 026/264] crypto: chacha20 - Fix keystream alignment for chacha20_block() Date: Thu, 23 Jun 2022 18:40:19 +0200 Message-Id: <20220623164344.809487453@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220623164344.053938039@linuxfoundation.org> References: <20220623164344.053938039@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Biggers commit 9f480faec58cd6197a007ea1dcac6b7c3daf1139 upstream. When chacha20_block() outputs the keystream block, it uses 'u32' stores directly. However, the callers (crypto/chacha20_generic.c and drivers/char/random.c) declare the keystream buffer as a 'u8' array, which is not guaranteed to have the needed alignment. Fix it by having both callers declare the keystream as a 'u32' array. For now this is preferable to switching over to the unaligned access macros because chacha20_block() is only being used in cases where we can easily control the alignment (stack buffers). Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman --- crypto/chacha20_generic.c | 6 +++--- drivers/char/random.c | 24 ++++++++++++------------ include/crypto/chacha20.h | 3 ++- lib/chacha20.c | 2 +- 4 files changed, 18 insertions(+), 17 deletions(-) --- a/crypto/chacha20_generic.c +++ b/crypto/chacha20_generic.c @@ -23,20 +23,20 @@ static inline u32 le32_to_cpuvp(const vo static void chacha20_docrypt(u32 *state, u8 *dst, const u8 *src, unsigned int bytes) { - u8 stream[CHACHA20_BLOCK_SIZE]; + u32 stream[CHACHA20_BLOCK_WORDS]; if (dst != src) memcpy(dst, src, bytes); while (bytes >= CHACHA20_BLOCK_SIZE) { chacha20_block(state, stream); - crypto_xor(dst, stream, CHACHA20_BLOCK_SIZE); + crypto_xor(dst, (const u8 *)stream, CHACHA20_BLOCK_SIZE); bytes -= CHACHA20_BLOCK_SIZE; dst += CHACHA20_BLOCK_SIZE; } if (bytes) { chacha20_block(state, stream); - crypto_xor(dst, stream, bytes); + crypto_xor(dst, (const u8 *)stream, bytes); } } --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -434,9 +434,9 @@ static int crng_init_cnt = 0; static unsigned long crng_global_init_time = 0; #define CRNG_INIT_CNT_THRESH (2*CHACHA20_KEY_SIZE) static void _extract_crng(struct crng_state *crng, - __u8 out[CHACHA20_BLOCK_SIZE]); + __u32 out[CHACHA20_BLOCK_WORDS]); static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA20_BLOCK_SIZE], int used); + __u32 tmp[CHACHA20_BLOCK_WORDS], int used); static void process_random_ready_list(void); static void _get_random_bytes(void *buf, int nbytes); @@ -981,7 +981,7 @@ static void crng_reseed(struct crng_stat unsigned long flags; int i, num; union { - __u8 block[CHACHA20_BLOCK_SIZE]; + __u32 block[CHACHA20_BLOCK_WORDS]; __u32 key[8]; } buf; @@ -1029,7 +1029,7 @@ static void crng_reseed(struct crng_stat } static void _extract_crng(struct crng_state *crng, - __u8 out[CHACHA20_BLOCK_SIZE]) + __u32 out[CHACHA20_BLOCK_WORDS]) { unsigned long v, flags, init_time; @@ -1049,7 +1049,7 @@ static void _extract_crng(struct crng_st spin_unlock_irqrestore(&crng->lock, flags); } -static void extract_crng(__u8 out[CHACHA20_BLOCK_SIZE]) +static void extract_crng(__u32 out[CHACHA20_BLOCK_WORDS]) { _extract_crng(select_crng(), out); } @@ -1059,7 +1059,7 @@ static void extract_crng(__u8 out[CHACHA * enough) to mutate the CRNG key to provide backtracking protection. */ static void _crng_backtrack_protect(struct crng_state *crng, - __u8 tmp[CHACHA20_BLOCK_SIZE], int used) + __u32 tmp[CHACHA20_BLOCK_WORDS], int used) { unsigned long flags; __u32 *s, *d; @@ -1071,14 +1071,14 @@ static void _crng_backtrack_protect(stru used = 0; } spin_lock_irqsave(&crng->lock, flags); - s = (__u32 *) &tmp[used]; + s = &tmp[used / sizeof(__u32)]; d = &crng->state[4]; for (i=0; i < 8; i++) *d++ ^= *s++; spin_unlock_irqrestore(&crng->lock, flags); } -static void crng_backtrack_protect(__u8 tmp[CHACHA20_BLOCK_SIZE], int used) +static void crng_backtrack_protect(__u32 tmp[CHACHA20_BLOCK_WORDS], int used) { _crng_backtrack_protect(select_crng(), tmp, used); } @@ -1086,7 +1086,7 @@ static void crng_backtrack_protect(__u8 static ssize_t extract_crng_user(void __user *buf, size_t nbytes) { ssize_t ret = 0, i = CHACHA20_BLOCK_SIZE; - __u8 tmp[CHACHA20_BLOCK_SIZE]; + __u32 tmp[CHACHA20_BLOCK_WORDS]; int large_request = (nbytes > 256); while (nbytes) { @@ -1672,7 +1672,7 @@ static void _warn_unseeded_randomness(co */ static void _get_random_bytes(void *buf, int nbytes) { - __u8 tmp[CHACHA20_BLOCK_SIZE]; + __u32 tmp[CHACHA20_BLOCK_WORDS]; trace_get_random_bytes(nbytes, _RET_IP_); @@ -2273,7 +2273,7 @@ u64 get_random_u64(void) batch = raw_cpu_ptr(&batched_entropy_u64); spin_lock_irqsave(&batch->batch_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u64) == 0) { - extract_crng((u8 *)batch->entropy_u64); + extract_crng((__u32 *)batch->entropy_u64); batch->position = 0; } ret = batch->entropy_u64[batch->position++]; @@ -2297,7 +2297,7 @@ u32 get_random_u32(void) batch = raw_cpu_ptr(&batched_entropy_u32); spin_lock_irqsave(&batch->batch_lock, flags); if (batch->position % ARRAY_SIZE(batch->entropy_u32) == 0) { - extract_crng((u8 *)batch->entropy_u32); + extract_crng(batch->entropy_u32); batch->position = 0; } ret = batch->entropy_u32[batch->position++]; --- a/include/crypto/chacha20.h +++ b/include/crypto/chacha20.h @@ -11,12 +11,13 @@ #define CHACHA20_IV_SIZE 16 #define CHACHA20_KEY_SIZE 32 #define CHACHA20_BLOCK_SIZE 64 +#define CHACHA20_BLOCK_WORDS (CHACHA20_BLOCK_SIZE / sizeof(u32)) struct chacha20_ctx { u32 key[8]; }; -void chacha20_block(u32 *state, void *stream); +void chacha20_block(u32 *state, u32 *stream); void crypto_chacha20_init(u32 *state, struct chacha20_ctx *ctx, u8 *iv); int crypto_chacha20_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keysize); --- a/lib/chacha20.c +++ b/lib/chacha20.c @@ -21,7 +21,7 @@ static inline u32 rotl32(u32 v, u8 n) return (v << n) | (v >> (sizeof(v) * 8 - n)); } -extern void chacha20_block(u32 *state, void *stream) +void chacha20_block(u32 *state, u32 *stream) { u32 x[16], *out = stream; int i;