From patchwork Fri Feb 21 07:42:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230857 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 A0353C35640 for ; Fri, 21 Feb 2020 08:25:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6D80E2467B for ; Fri, 21 Feb 2020 08:25:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582273556; bh=7P2vlFybEQGvQnGZvdak6Xt5WNMRnhmHfVS2Glgdc78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CXfXgK1RMtwzRPq5PXMbaGuS2ukdu9HaRjPyaknfTcHedWl694iEXsfqvowNO+8uQ xekBxDhSwfNMcNGDIzIuoT/OGEmIVT8bl/yCW8vRASPIq1YTt4hsHgJ2OiZJXys9wk n+Vjjk+Ux9Ijx6D/JJthEzFnTiuEO5z28U6FG/w0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388830AbgBUIZz (ORCPT ); Fri, 21 Feb 2020 03:25:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:37570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388334AbgBUIYz (ORCPT ); Fri, 21 Feb 2020 03:24:55 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4499246A6; Fri, 21 Feb 2020 08:24:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582273495; bh=7P2vlFybEQGvQnGZvdak6Xt5WNMRnhmHfVS2Glgdc78=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1KVuvKbhHReysdM7Kbez3KklFd/IRHiIcMHNjs/F/PS+JngjOExfKQ4T54ffDLMDD SvLrYA7vxvhIkGHazqQ+Qx+KS7ddsy6sJ7f4H2xqHJrrtYUKVXYOKN51McJSenTZ9H o2jZ6WWjKdLnq0h4taJslbhNo1Z4vtALY+vBfIKc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Averin , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.19 168/191] bpf: map_seq_next should always increase position index Date: Fri, 21 Feb 2020 08:42:21 +0100 Message-Id: <20200221072310.880540739@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072250.732482588@linuxfoundation.org> References: <20200221072250.732482588@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vasily Averin [ Upstream commit 90435a7891a2259b0f74c5a1bc5600d0d64cba8f ] If seq_file .next fuction does not change position index, read after some lseek can generate an unexpected output. See also: https://bugzilla.kernel.org/show_bug.cgi?id=206283 v1 -> v2: removed missed increment in end of function Signed-off-by: Vasily Averin Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/eca84fdd-c374-a154-d874-6c7b55fc3bc4@virtuozzo.com Signed-off-by: Sasha Levin --- kernel/bpf/inode.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c index dc9d7ac8228db..c04815bb15cc1 100644 --- a/kernel/bpf/inode.c +++ b/kernel/bpf/inode.c @@ -198,6 +198,7 @@ static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) void *key = map_iter(m)->key; void *prev_key; + (*pos)++; if (map_iter(m)->done) return NULL; @@ -210,8 +211,6 @@ static void *map_seq_next(struct seq_file *m, void *v, loff_t *pos) map_iter(m)->done = true; return NULL; } - - ++(*pos); return key; }