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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1D1D9C433EF for ; Sun, 23 Jan 2022 15:24:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=QEd8jwU/BBFlVMiZMlkpM6i9aNBXwDDkPAhTQQnOHD8=; b=T1imbM9VLpO9EI nlHNAVZJ/AOa3BThA02gdrORlXTnWMtCtIGtulFe9a/9BdTA1l2D0x/YzFmbVwlfIvwgD8pnN0ItQ 6BZW4MkoiibsMeMDGkoXMuYikW98jQUNSpt5XZKbAv33Bh4Sgu2iUwbU63qPzgRChKERfk7cMR3TI 4mXfXxrabF6ik/FpHiizA3IucaaTEKJ9lC5hncqPE0snzw5df4LHO+W8e7NBFxyoXlY+ehJqeNgdM gPFG57ftnoOFSZU6VZPlchsGJiRl/eDXL76YF1ifTdRMCnfw4dadShB+N4+l42mftOBSx3ZmAcJUd 6E+UE+jgMZmHa9c+FxVg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nBehy-0013HJ-FR; Sun, 23 Jan 2022 15:23:10 +0000 Received: from relay11.mail.gandi.net ([217.70.178.231]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nBehr-0013GH-Iu for linux-mtd@lists.infradead.org; Sun, 23 Jan 2022 15:23:05 +0000 Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id F2A67100005; Sun, 23 Jan 2022 15:22:56 +0000 (UTC) From: Miquel Raynal To: Dan Carpenter , Joern Engel , yangerkun Cc: Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , linux-mtd@lists.infradead.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH v2] mtd: phram: Prevent divide by zero bug in phram_setup() Date: Sun, 23 Jan 2022 16:22:56 +0100 Message-Id: <20220123152256.529296-1-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20220121115505.GI1978@kadam> References: MIME-Version: 1.0 X-linux-mtd-patch-notification: thanks X-linux-mtd-patch-commit: b'4f82eb6b4aec9d584c9dd370087db7a87c88bcb6' X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220123_072303_797350_64E2EB41 X-CRM114-Status: UNSURE ( 9.08 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Fri, 2022-01-21 at 11:55:05 UTC, Dan Carpenter wrote: > The problem is that "erasesize" is a uint64_t type so it might be > non-zero but the lower 32 bits are zero so when it's truncated, > "(uint32_t)erasesize", then that value is zero. This leads to a > divide by zero bug. > > Avoid the bug by delaying the divide until after we have validated > that "erasesize" is non-zero and within the uint32_t range. > > Fixes: dc2b3e5cbc80 ("mtd: phram: use div_u64_rem to stop overwrite len in phram_setup") > Signed-off-by: Dan Carpenter Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next, thanks. Miquel ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/