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 55990EEB56D for ; Fri, 8 Sep 2023 19:32:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344827AbjIHTcJ (ORCPT ); Fri, 8 Sep 2023 15:32:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344854AbjIHTcD (ORCPT ); Fri, 8 Sep 2023 15:32:03 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4F2B1BF5; Fri, 8 Sep 2023 12:31:37 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4DB8C433C7; Fri, 8 Sep 2023 19:31:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694201497; bh=0RaSnF4YoHbPKw576tddhAEd5R8emBX3CjP2ENAamoY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X7W601Tb8h6eEkyzRVopFoA2FEuJ4jOCrVPgaH7SASAzoe9mwMbOdw4BGqMZKl/r2 QSIK6QFagyo3MXfaKnTYJfDrc8TPZJqC1jLjrse4yyhmK1MHItGs+xWFg1mn2MTe46 XCT7b0SHufzcAuhlh7c16tDlffSvn0WflvF265Xo6SQrNVpXn3RNbzdAfGrTyqlmou lBUyQjZTtbfSkDuoP1EIvPkzbzd/7uBUEIfzvEBzpwBdheHLPrRk++6HWY+Y2Htgmg NVHYAdV628vSoKnpkKvYtltRQQXlI19CdmcNqJ4gqxyRDdw1ihE2Rd0rcDKAc3wtwv sIAiim2E4dfXA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kent Overstreet , Jens Axboe , linux-block@vger.kernel.org, Sasha Levin Subject: [PATCH AUTOSEL 6.5 31/36] block: Allow bio_iov_iter_get_pages() with bio->bi_bdev unset Date: Fri, 8 Sep 2023 15:28:42 -0400 Message-Id: <20230908192848.3462476-31-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908192848.3462476-1-sashal@kernel.org> References: <20230908192848.3462476-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.5.2 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kent Overstreet [ Upstream commit 168145f617d57bf4e474901b7ffa869337a802e6 ] bio_iov_iter_get_pages() trims the IO based on the block size of the block device the IO will be issued to. However, bcachefs is a multi device filesystem; when we're creating the bio we don't yet know which block device the bio will be submitted to - we have to handle the alignment checks elsewhere. Thus this is needed to avoid a null ptr deref. Signed-off-by: Kent Overstreet Cc: Jens Axboe Cc: linux-block@vger.kernel.org Link: https://lore.kernel.org/r/20230813182636.2966159-3-kent.overstreet@linux.dev Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/bio.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/block/bio.c b/block/bio.c index 8672179213b93..4b65be00b60d3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1252,7 +1252,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) struct page **pages = (struct page **)bv; ssize_t size, left; unsigned len, i = 0; - size_t offset, trim; + size_t offset; int ret = 0; /* @@ -1281,10 +1281,12 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) nr_pages = DIV_ROUND_UP(offset + size, PAGE_SIZE); - trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1); - iov_iter_revert(iter, trim); + if (bio->bi_bdev) { + size_t trim = size & (bdev_logical_block_size(bio->bi_bdev) - 1); + iov_iter_revert(iter, trim); + size -= trim; + } - size -= trim; if (unlikely(!size)) { ret = -EFAULT; goto out; -- 2.40.1