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 28BD4C433EF for ; Sun, 23 Jan 2022 00:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235316AbiAWAQ7 (ORCPT ); Sat, 22 Jan 2022 19:16:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36706 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231836AbiAWAPi (ORCPT ); Sat, 22 Jan 2022 19:15:38 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B40EC061768; Sat, 22 Jan 2022 16:13:53 -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 sin.source.kernel.org (Postfix) with ESMTPS id F0ECECE0AD1; Sun, 23 Jan 2022 00:13:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90FD7C004E1; Sun, 23 Jan 2022 00:13:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642896831; bh=izXuRLTqqf53tu6dekzU+DqbvdILLQrv0sYd8FrFK8o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XoEEIsCEaSl854DrQLPfdYTinF5Qxo1n5AzmB2Z8alEmuygXb6PgwcSHknADe1wif vJsBJ5tf2dCH+t4PbjU52p+dIxj/9WxjkQaOk3wsIBV/Rol6Yxyz8MKnW8sHVXWfcK d9uefpz1LqCh9GH5JsmbpwI1pHs0YCaGaUB4s9IQHmDNASAGUSAhB0A6qRmnedGGd4 fr79SC+cmBz5DaZDz8/kuK8mAnTFtTmANKuOqnfwxpTjoDC1ovyVgoQmCTsLELxYNc MiKqxj2XoXgBFpTJ4flj0ibAtQqY8EOrGAi+AQZzM8GdYl+2Vg4WYycRpqMQN1fbiO TmBtHh5G57JWQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: OGAWA Hirofumi , syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com, Ming Lei , Jens Axboe , Sasha Levin , linux-block@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 8/8] block: Fix wrong offset in bio_truncate() Date: Sat, 22 Jan 2022 19:13:23 -0500 Message-Id: <20220123001323.2460719-8-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220123001323.2460719-1-sashal@kernel.org> References: <20220123001323.2460719-1-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-kernel@vger.kernel.org From: OGAWA Hirofumi [ Upstream commit 3ee859e384d453d6ac68bfd5971f630d9fa46ad3 ] bio_truncate() clears the buffer outside of last block of bdev, however current bio_truncate() is using the wrong offset of page. So it can return the uninitialized data. This happened when both of truncated/corrupted FS and userspace (via bdev) are trying to read the last of bdev. Reported-by: syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com Signed-off-by: OGAWA Hirofumi Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/875yqt1c9g.fsf@mail.parknet.co.jp Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/bio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index cb38d6f3acceb..1c52d0196e15c 100644 --- a/block/bio.c +++ b/block/bio.c @@ -569,7 +569,8 @@ void bio_truncate(struct bio *bio, unsigned new_size) offset = new_size - done; else offset = 0; - zero_user(bv.bv_page, offset, bv.bv_len - offset); + zero_user(bv.bv_page, bv.bv_offset + offset, + bv.bv_len - offset); truncated = true; } done += bv.bv_len; -- 2.34.1