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 69F79C77B7F for ; Tue, 16 May 2023 22:51:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230341AbjEPWvN (ORCPT ); Tue, 16 May 2023 18:51:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36250 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229475AbjEPWvL (ORCPT ); Tue, 16 May 2023 18:51:11 -0400 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFEDC6E9D for ; Tue, 16 May 2023 15:51:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1684277469; x=1715813469; h=from:to:cc:subject:date:message-id; bh=bnlHaZuttI+Cn/fZ2ttTZGBxQdXXNPCgcrMnVd163Hg=; b=KFxMxWnh79dGLR5+MdlEFGJMgpJ4HH9oi+XHXftSzPuytzf20TkKQlxp C7Ol7Yke96AOjhJD7XxKzYchT0jomf8etrgx4pL2ZUWr5Er5cgeoaZV0C 6lMAaHIWF1u+IJitUFIIRh6M5Ax7qdxH22IepJROTC2/+U2boOFhoRyhL 4sx46u1DQNHVuLQ39bPB8wPz1Y6nFsFjpixvGLXXOwnUkbCeHPUUcDQB5 MeijqLaxKDadDRbRCC4Lhn0wlM0WFWclyWtIWKaTsF0PPdeFzg3C4tqtI lh8utTnes4A9PUkspJw7bIzPhcfbhCBMAP6jYB75vSg9xXxEOaGfr0/sb w==; X-IronPort-AV: E=McAfee;i="6600,9927,10712"; a="350448823" X-IronPort-AV: E=Sophos;i="5.99,280,1677571200"; d="scan'208";a="350448823" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 May 2023 15:51:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10712"; a="845846539" X-IronPort-AV: E=Sophos;i="5.99,280,1677571200"; d="scan'208";a="845846539" Received: from wopr.jf.intel.com ([10.54.75.136]) by fmsmga001.fm.intel.com with ESMTP; 16 May 2023 15:51:10 -0700 From: Todd Brandt To: miquel.raynal@bootlin.com, linux-kernel@vger.kernel.org Cc: todd.e.brandt@linux.intel.com, todd.e.brandt@intel.com, pratyush@kernel.org, tudor.ambarus@linaro.org Subject: [PATCH] MTD SPI-NOR: BUG FIX of divide by zero in new n_banks value Date: Tue, 16 May 2023 15:51:08 -0700 Message-Id: <20230516225108.29194-1-todd.e.brandt@intel.com> X-Mailer: git-send-email 2.17.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While testing 6.4-rc1 on our Lenovo Thinkpad X1 I discovered that freeze, suspend, and shutdown, all hang the system. I bisected it to an addition made to the MTD spi-nor code. The new "n_banks" value is being divided into without a proper check.. Thus on certain systems this causes a divide by zero hang. Reported-and-tested-by: Todd Brandt Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217448 Fixes: 9d6c5d64f028 ("mtd: spi-nor: Introduce the concept of bank") Signed-off-by: Todd Brandt --- drivers/mtd/spi-nor/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 0bb0ad14a2fc..084117959be4 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2921,7 +2921,10 @@ static void spi_nor_late_init_params(struct spi_nor *nor) if (nor->flags & SNOR_F_HAS_LOCK && !nor->params->locking_ops) spi_nor_init_default_locking_ops(nor); - nor->params->bank_size = div64_u64(nor->params->size, nor->info->n_banks); + if (nor->info->n_banks > 0) + nor->params->bank_size = div64_u64(nor->params->size, nor->info->n_banks); + else + nor->params->bank_size = 0; } /** -- 2.17.1