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 26B1CC76196 for ; Mon, 3 Apr 2023 14:22:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233128AbjDCOWg (ORCPT ); Mon, 3 Apr 2023 10:22:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233134AbjDCOWf (ORCPT ); Mon, 3 Apr 2023 10:22:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E682E2D7C2 for ; Mon, 3 Apr 2023 07:22:11 -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 80864B81BAE for ; Mon, 3 Apr 2023 14:22:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEA72C433EF; Mon, 3 Apr 2023 14:22:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680531730; bh=RuYnVTJwWCkgS5pZsTRyfgbm1jPX/9A6YF9I++YlZ7Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=v/AoAcL6EcbkustODWHvPwUsLshbrIgBvjr1ufw6WvpLAtFqJcpWIOf5YfUojoS1y TDGJQQS9nPYpodigjHNaMZ/nh5pjYiA6ctwc1+H0LhFLSBcWux1LJ9apymPlkOliLp 64tvevt5BBK/b0ONa6NfLK0ACjJ6SSCtdDxUk/BU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , NeilBrown , Song Liu , Sasha Levin Subject: [PATCH 5.4 062/104] md: avoid signed overflow in slot_store() Date: Mon, 3 Apr 2023 16:08:54 +0200 Message-Id: <20230403140406.686598036@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230403140403.549815164@linuxfoundation.org> References: <20230403140403.549815164@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: NeilBrown [ Upstream commit 3bc57292278a0b6ac4656cad94c14f2453344b57 ] slot_store() uses kstrtouint() to get a slot number, but stores the result in an "int" variable (by casting a pointer). This can result in a negative slot number if the unsigned int value is very large. A negative number means that the slot is empty, but setting a negative slot number this way will not remove the device from the array. I don't think this is a serious problem, but it could cause confusion and it is best to fix it. Reported-by: Dan Carpenter Signed-off-by: NeilBrown Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index aa2993d5d5d38..64558991ce0a0 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3082,6 +3082,9 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len) err = kstrtouint(buf, 10, (unsigned int *)&slot); if (err < 0) return err; + if (slot < 0) + /* overflow */ + return -ENOSPC; } if (rdev->mddev->pers && slot == -1) { /* Setting 'slot' on an active array requires also -- 2.39.2