From patchwork Fri Jun 21 16:59:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13707865 X-Patchwork-Delegate: herbert@gondor.apana.org.au Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4AA27166311; Fri, 21 Jun 2024 17:00:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718989217; cv=none; b=GrDV7To27KVToUNDynYa7jiTx4GF3srIgV6EM+uYM0Dm7FlGNPqyoR1qo9UJUyz4Xu3EYXmPhARwENAjufMgOMVwMnVy+eB7os69ak2K4z4AbTUv7H63/u4ZIv27JiHggeyPkeUxhTqaDo4c6sxWCLv55vnWXedK5GKbtE9EmQE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718989217; c=relaxed/simple; bh=6USdTOOyYM3FNFIuW1a3O/WfkiZlhPxeGJEgqz38Sgw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=C5ZqXFmn11TYt4okMFOClrAkQI/TQi9Bzw/Q3Cfg9vcCf/6KEQzEBmn8cTRmNZCM80/LrxK+OJzvzmm2oepRKmg3eL3tIJoLhYPIq3N9ypgXroAhlIH9P4sz0a5zy7slzcaLjsWZeKIZayrgoMeyWFxK5I8olpSSA0qKOmkNyog= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=O8PuJMKn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="O8PuJMKn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 76F91C4AF0A; Fri, 21 Jun 2024 17:00:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718989216; bh=6USdTOOyYM3FNFIuW1a3O/WfkiZlhPxeGJEgqz38Sgw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O8PuJMKnPBgqE3pbF/On9Owe+WUuzNwk0hDGwJXOtQrMk5mBHXQV6/1S7KKFuAbTr ncV0uRvdKzPyfDvDs6z48a9acujSdMvHZhr2oAjGGUIvlnfWBMMUD0F5+LvBbuIWJi 127sxDcxkVhi2InXsKt39C2RKrKedcoyG6LKB2Rj+4PihsopUgeF4aGdH93h3wUj+1 vhgZxWK1axYT0huzF2/TKVXk0LFo0ovupCFQikNVaDg+n0IatuunwEbytW5eAhlpXk iobRLpyA8y3shjRfpXqDGGcXYCnoP1XBAuaV1LLZ+trjiOiXbf2fcHdCzbFZwRDfKP ogECHWVRCV18w== From: Eric Biggers To: linux-crypto@vger.kernel.org, fsverity@lists.linux.dev, dm-devel@lists.linux.dev Cc: x86@kernel.org, linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Sami Tolvanen , Bart Van Assche , Herbert Xu , Alasdair Kergon , Mike Snitzer , Mikulas Patocka Subject: [PATCH v6 02/15] crypto: testmgr - generate power-of-2 lengths more often Date: Fri, 21 Jun 2024 09:59:09 -0700 Message-ID: <20240621165922.77672-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240621165922.77672-1-ebiggers@kernel.org> References: <20240621165922.77672-1-ebiggers@kernel.org> Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Eric Biggers Implementations of hash functions often have special cases when lengths are a multiple of the hash function's internal block size (e.g. 64 for SHA-256, 128 for SHA-512). Currently, when the fuzz testing code generates lengths, it doesn't prefer any length mod 64 over any other. This limits the coverage of these special cases. Therefore, this patch updates the fuzz testing code to generate power-of-2 lengths and divide messages exactly in half a bit more often. Reviewed-by: Sami Tolvanen Acked-by: Ard Biesheuvel Signed-off-by: Eric Biggers --- crypto/testmgr.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/crypto/testmgr.c b/crypto/testmgr.c index a780b615f8c6..f02cb075bd68 100644 --- a/crypto/testmgr.c +++ b/crypto/testmgr.c @@ -914,18 +914,24 @@ static unsigned int generate_random_length(struct rnd_state *rng, { unsigned int len = prandom_u32_below(rng, max_len + 1); switch (prandom_u32_below(rng, 4)) { case 0: - return len % 64; + len %= 64; + break; case 1: - return len % 256; + len %= 256; + break; case 2: - return len % 1024; + len %= 1024; + break; default: - return len; + break; } + if (len && prandom_u32_below(rng, 4) == 0) + len = rounddown_pow_of_two(len); + return len; } /* Flip a random bit in the given nonempty data buffer */ static void flip_random_bit(struct rnd_state *rng, u8 *buf, size_t size) { @@ -1017,10 +1023,12 @@ static char *generate_random_sgl_divisions(struct rnd_state *rng, unsigned int this_len; const char *flushtype_str; if (div == &divs[max_divs - 1] || prandom_bool(rng)) this_len = remaining; + else if (prandom_u32_below(rng, 4) == 0) + this_len = (remaining + 1) / 2; else this_len = prandom_u32_inclusive(rng, 1, remaining); div->proportion_of_total = this_len; if (prandom_u32_below(rng, 4) == 0)