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 37651EEB566 for ; Fri, 8 Sep 2023 19:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344988AbjIHTgq (ORCPT ); Fri, 8 Sep 2023 15:36:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243999AbjIHTgj (ORCPT ); Fri, 8 Sep 2023 15:36:39 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC7C61FC4; Fri, 8 Sep 2023 12:36:18 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FDEFC113C9; Fri, 8 Sep 2023 19:35:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694201726; bh=uY/qmFyaXvaAdfAYOYiCEHjFhCYv5lZ7VmTD1xgHoIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pdJupR2AihKhrM2bfYC832qeCDdKaJn8zz1aHBYQvmjRSb78olOEwlWSEVfx8gclD 4FIpiFMvZQEE2yNDXGplOB8uDZNpkheCjNKKchmfmbV2MWPQRnnKTxvKXZIi00VGjl a+aTBEMBEbBH2LykPFa1TmSefEpTJM1r9Du9goy8nxCbVHqOELDrvMxTt9J5wiYPkz CilQd9yra/UsY0DLw86uhMGDvRv0BdXyiqtpwhr2yzYZfDhDI7Gw6wHmgISWEUkXL6 qcureB/3oZXoaE6YdZP+imThBInTjGP6AOnGIULb1T/bXGDmH6TNiJd42ucmygfaSV ZjKA5JojqNEeg== 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 6.1 20/22] block: Allow bio_iov_iter_get_pages() with bio->bi_bdev unset Date: Fri, 8 Sep 2023 15:34:04 -0400 Message-Id: <20230908193407.3463368-20-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230908193407.3463368-1-sashal@kernel.org> References: <20230908193407.3463368-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.52 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@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 d5cd825d6efc0..54c8d11f09663 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1198,7 +1198,7 @@ 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; /* @@ -1223,10 +1223,12 @@ 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