From nobody Sat Apr 20 01:27:34 2024 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 C779CC6FA82 for ; Fri, 23 Sep 2022 10:27:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230369AbiIWK0i (ORCPT ); Fri, 23 Sep 2022 06:26:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48316 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230216AbiIWK0b (ORCPT ); Fri, 23 Sep 2022 06:26:31 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34266122634 for ; Fri, 23 Sep 2022 03:26:31 -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 dfw.source.kernel.org (Postfix) with ESMTPS id C3E7F6123F for ; Fri, 23 Sep 2022 10:26:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA911C433D6 for ; Fri, 23 Sep 2022 10:26:29 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="M8R6qgI2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1663928788; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=QgWPyzZNjKxy0P2YXKLOdQ3Qr9+tTm5v6GiBVGnh5ts=; b=M8R6qgI2/KFogmJnRbiITSqWktoq0R5NDFvI9tkKeJfSsikLsrjkIwC3+neOP3mvb8sRaX 5HAaYVqc++JhG85Ke8PPfY1iuq3c5pSPdnridNXCxD6pY0muffCYfByUQrRA5dSFP09vOt RsOQSaqK8TTSjC3kD+q1C96G5fF0HDs= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id 8ecdf6b5 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Fri, 23 Sep 2022 10:26:28 +0000 (UTC) From: "Jason A. Donenfeld" To: linux-kernel@vger.kernel.org Cc: "Jason A. Donenfeld" Subject: [PATCH v2] random: clamp credited irq bits to maximum mixed Date: Fri, 23 Sep 2022 12:26:15 +0200 Message-Id: <20220923102615.3890383-1-Jason@zx2c4.com> In-Reply-To: <20220923092204.3818698-1-Jason@zx2c4.com> References: <20220923092204.3818698-1-Jason@zx2c4.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since the most that's mixed into the pool is sizeof(long)*2, don't credit more than that many bytes of entropy. Fixes: e3e33fc2ea7f ("random: do not use input pool from hard IRQs") Signed-off-by: Jason A. Donenfeld --- drivers/char/random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/random.c b/drivers/char/random.c index 520a385c7dab..2f370aa248b2 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1004,7 +1004,7 @@ static void mix_interrupt_randomness(struct work_stru= ct *work) local_irq_enable(); =20 mix_pool_bytes(pool, sizeof(pool)); - credit_init_bits(max(1u, (count & U16_MAX) / 64)); + credit_init_bits(clamp_t(unsigned int, (count & U16_MAX) / 64, 1, sizeof(= pool) * 8)); =20 memzero_explicit(pool, sizeof(pool)); } --=20 2.37.3