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 0FAF0C433F5 for ; Mon, 31 Jan 2022 11:17:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376512AbiAaLR1 (ORCPT ); Mon, 31 Jan 2022 06:17:27 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:48990 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376548AbiAaLP3 (ORCPT ); Mon, 31 Jan 2022 06:15:29 -0500 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 dfw.source.kernel.org (Postfix) with ESMTPS id 9971A611E3; Mon, 31 Jan 2022 11:15:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 721A5C340E8; Mon, 31 Jan 2022 11:15:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627728; bh=uYmonM8kWqr/zkESPNyhoZSN6/qpNngeaDY6ehuJrd8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mn0a1yG0c/jf0NTFIUPCCp0Zj/3UChpSHt4R4RujfCVrEmE+CP45I1ZPD9mli5cuC OH+OLsY0uc0yNlL67Gn8o17TQPKigZt4NMwvx8f1Z4HGbUd80k1hbdmeQLTZ0oSQzJ jPptOV6K9fKzf1pZ2Hd/uje7anHAiF/TxRKJ9sBU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ac94ae5f68b84197f41c@syzkaller.appspotmail.com, OGAWA Hirofumi , Ming Lei , Jens Axboe Subject: [PATCH 5.15 171/171] block: Fix wrong offset in bio_truncate() Date: Mon, 31 Jan 2022 11:57:16 +0100 Message-Id: <20220131105235.797805988@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220131105229.959216821@linuxfoundation.org> References: <20220131105229.959216821@linuxfoundation.org> User-Agent: quilt/0.66 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: OGAWA Hirofumi commit 3ee859e384d453d6ac68bfd5971f630d9fa46ad3 upstream. 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: Greg Kroah-Hartman --- block/bio.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/block/bio.c +++ b/block/bio.c @@ -567,7 +567,8 @@ void bio_truncate(struct bio *bio, unsig 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;