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 D8262C46467 for ; Mon, 16 Jan 2023 17:14:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234377AbjAPROs (ORCPT ); Mon, 16 Jan 2023 12:14:48 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39186 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234324AbjAPRNC (ORCPT ); Mon, 16 Jan 2023 12:13:02 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 580344B1B7 for ; Mon, 16 Jan 2023 08:53:20 -0800 (PST) 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 19AF9B80E95 for ; Mon, 16 Jan 2023 16:53:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 747E0C433EF; Mon, 16 Jan 2023 16:53:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1673887997; bh=KZFU1leGzQQD6HVHzCIQHyBf69zaJo1yZHVmC8bGzM0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LvWOCvl0PPgTK7RZE59WpW7f4YgBpWjtMwPqWF3fpi6sqsAlnqPQd6zjPZOB7wKnO 2/2yoY/A3esti287rAeN0VFEV68Wq8YhTV6iey4s93psI93t6G+DvG3GjfoC2Vr3VU rqC1C0Pe1SS3MTz5Vdv4eZO9TkcMY+yOFTk9qTZY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Zhong , Song Liu , Sasha Levin Subject: [PATCH 4.19 332/521] drivers/md/md-bitmap: check the return value of md_bitmap_get_counter() Date: Mon, 16 Jan 2023 16:49:54 +0100 Message-Id: <20230116154902.030098499@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230116154847.246743274@linuxfoundation.org> References: <20230116154847.246743274@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: Li Zhong [ Upstream commit 3bd548e5b819b8c0f2c9085de775c5c7bff9052f ] Check the return value of md_bitmap_get_counter() in case it returns NULL pointer, which will result in a null pointer dereference. v2: update the check to include other dereference Signed-off-by: Li Zhong Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/md-bitmap.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c index 7cf9d34ce20e..157a1735d7b7 100644 --- a/drivers/md/md-bitmap.c +++ b/drivers/md/md-bitmap.c @@ -2191,20 +2191,23 @@ int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, if (set) { bmc_new = md_bitmap_get_counter(&bitmap->counts, block, &new_blocks, 1); - if (*bmc_new == 0) { - /* need to set on-disk bits too. */ - sector_t end = block + new_blocks; - sector_t start = block >> chunkshift; - start <<= chunkshift; - while (start < end) { - md_bitmap_file_set_bit(bitmap, block); - start += 1 << chunkshift; + if (bmc_new) { + if (*bmc_new == 0) { + /* need to set on-disk bits too. */ + sector_t end = block + new_blocks; + sector_t start = block >> chunkshift; + + start <<= chunkshift; + while (start < end) { + md_bitmap_file_set_bit(bitmap, block); + start += 1 << chunkshift; + } + *bmc_new = 2; + md_bitmap_count_page(&bitmap->counts, block, 1); + md_bitmap_set_pending(&bitmap->counts, block); } - *bmc_new = 2; - md_bitmap_count_page(&bitmap->counts, block, 1); - md_bitmap_set_pending(&bitmap->counts, block); + *bmc_new |= NEEDED_MASK; } - *bmc_new |= NEEDED_MASK; if (new_blocks < old_blocks) old_blocks = new_blocks; } -- 2.35.1