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 B65F2C6FD1C for ; Wed, 22 Mar 2023 20:08:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231839AbjCVUIR (ORCPT ); Wed, 22 Mar 2023 16:08:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231856AbjCVUH6 (ORCPT ); Wed, 22 Mar 2023 16:07:58 -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 1EC5764A92; Wed, 22 Mar 2023 13:01:59 -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 BEB43B81DEF; Wed, 22 Mar 2023 20:01:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D6D2AC433D2; Wed, 22 Mar 2023 20:01:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1679515287; bh=p1R/Ad0he83YE2u1+oXwn0yoaMGKewX0nYOTQhn+ZNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VFi92h63xtqyXKRR9SNuHSYx1Fgr4DVxwSXAfGSNTfF/7m8bUB2QOXMzoh48JRvkQ yojcdYAEw6Vtw8CoWnEdvsienDhFqDrA5RIzyOmNtzNNyjkQLyY0K0Gb8QIbhBBXT8 ktCcy+8WnSav+8zqgCLGYk06V/cgxasHFBgzAPR74yHxNJHCx/mHq8HBjXLe4PPlvw XCEt1pnq5F+nclTDlNt4i01OVg9A6oU2Hl7cuVLaV9vd46CGQZx+iP5ZnPZ9AhU5VE Ti1aImscV4asQdypaI/g5TwJp2r0BB41PwLJAqBamos1Tz1PoRDui0grrihDESXN/S ON9UjWeHyZ0dw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: NeilBrown , Dan Carpenter , Song Liu , Sasha Levin , linux-raid@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 03/16] md: avoid signed overflow in slot_store() Date: Wed, 22 Mar 2023 16:01:07 -0400 Message-Id: <20230322200121.1997157-3-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230322200121.1997157-1-sashal@kernel.org> References: <20230322200121.1997157-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-raid@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 9e54b865f30da..bd0c9dfac9815 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -3189,6 +3189,9 @@ 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