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 X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 623ADC07E9C for ; Sat, 10 Jul 2021 02:19:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F344613CF for ; Sat, 10 Jul 2021 02:19:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232585AbhGJCWX (ORCPT ); Fri, 9 Jul 2021 22:22:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:38804 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232437AbhGJCVt (ORCPT ); Fri, 9 Jul 2021 22:21:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 80DC361419; Sat, 10 Jul 2021 02:19:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625883544; bh=HAf0RaDTzDP5F1hXJJDZbhvANHYbr8yOdM2uGhwNgiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PWzZ9pstKDLQjTYsSSze3jwcJ9ZCjEA3cg5DX6CXBiciUIn9NZVnsGBcMA9MvJ5NX 0U/XBYFA+UlKfCkT0pBEHVA9XSh54BDTez6fmacEjy4ldMamP47XraSwmuyoPEXVbd ojVX5hLcLEzGrQCtVGjsw8Vxb65LSOnE9+K7NXhnCUSDObMmh4whTqyvNpFA5tLt3K TJRSBxgBlwyJBIXFeZkVy5v/HeMBIMoSFRw+qRO8VPEAEyth3OgACx5gqaX1nTmmh4 wXmApafNDucJ3FztGSrAkdPQUcJgnLya7Hl7+z+klV4tLIM0xK8vjPx4mrmLMs7Dwe xZGLRZwOl86JA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Al Viro , Sasha Levin Subject: [PATCH AUTOSEL 5.13 055/114] iov_iter_advance(): use consistent semantics for move past the end Date: Fri, 9 Jul 2021 22:16:49 -0400 Message-Id: <20210710021748.3167666-55-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710021748.3167666-1-sashal@kernel.org> References: <20210710021748.3167666-1-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: stable@vger.kernel.org From: Al Viro [ Upstream commit 3b3fc051cd2cba42bf736fa62780857d251a1236 ] asking to advance by more than we have left in the iov_iter should move to the very end; it should *not* leave negative i->count and it should not spew into syslog, etc. - it's a legitimate operation. Signed-off-by: Al Viro Signed-off-by: Sasha Levin --- lib/iov_iter.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index c701b7a187f2..82a889283eca 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1092,8 +1092,6 @@ static inline void pipe_truncate(struct iov_iter *i) static void pipe_advance(struct iov_iter *i, size_t size) { struct pipe_inode_info *pipe = i->pipe; - if (unlikely(i->count < size)) - size = i->count; if (size) { struct pipe_buffer *buf; unsigned int p_mask = pipe->ring_size - 1; @@ -1134,6 +1132,8 @@ static void iov_iter_bvec_advance(struct iov_iter *i, size_t size) void iov_iter_advance(struct iov_iter *i, size_t size) { + if (unlikely(i->count < size)) + size = i->count; if (unlikely(iov_iter_is_pipe(i))) { pipe_advance(i, size); return; @@ -1143,7 +1143,6 @@ void iov_iter_advance(struct iov_iter *i, size_t size) return; } if (unlikely(iov_iter_is_xarray(i))) { - size = min(size, i->count); i->iov_offset += size; i->count -= size; return; -- 2.30.2