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 0FAE8C433EF for ; Sun, 23 Jan 2022 00:13:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235485AbiAWANC (ORCPT ); Sat, 22 Jan 2022 19:13:02 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:36544 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235193AbiAWAMP (ORCPT ); Sat, 22 Jan 2022 19:12:15 -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 542E260F9F; Sun, 23 Jan 2022 00:12:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DE1C1C340E2; Sun, 23 Jan 2022 00:12:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1642896734; bh=fZypQpgkRfInoHjS2iRjdcBucBEwTWKnEXuwoq78lFE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p32UkSUEoYFwR5iF6/gwU2slKJ0zQv9fLe1ZfuzH89ek4VJcFo0Kllt0P+d1JKaGT UtVaRcN4dBpAvM76+fgPfPLQ3C0se342z0JFhJL4x4TsCXdn7hvxX5iH33Vy34rqMq bTM7UwN6bcZDhi4pvfCmM9OhDHh1HE95ctlfiN8A12rXDRogIcCPxsyYuipRyGAQYW lDAAxgGkHRpXN2ybN4RrHTTIRPVD9L3YeVUJeGel7ETgkGdV3eyj6Tq+sjBBfdRuE9 Q59VYzO/anXrssC7JN39B5U/2pY69W7H2PhbbXKjCxzSNZA1q6TCUus/M/Jug4ji5p 0Rz5ZfYCguikw== 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 5.16 19/19] block: Fix wrong offset in bio_truncate() Date: Sat, 22 Jan 2022 19:11:12 -0500 Message-Id: <20220123001113.2460140-19-sashal@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220123001113.2460140-1-sashal@kernel.org> References: <20220123001113.2460140-1-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 15ab0d6d1c06e..99cad261ec531 100644 --- a/block/bio.c +++ b/block/bio.c @@ -569,7 +569,8 @@ static 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