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=-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 BDD5AC83007 for ; Tue, 28 Apr 2020 18:32:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E716217D8 for ; Tue, 28 Apr 2020 18:32:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098729; bh=eVdIKm2kuMC/roZW1kDDMJeJ4ns4NVmx3rwtzKl9sLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MSXZoOdw4YarVI5TCojZTJJ+Oe4EkLXNvxFUVI4jFezxHzz6Atk3AoYYgO5wH4C3p OhUaDPGk0XObSZ12VJlM1RBRtBNsV9pIRkTq5+flm19eSMIbgF3Wy3uvLcrUbMAY5s 889phJK7aQjjQvyi1gcOCxDo6bvSUnXOmwl7Ir20= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728951AbgD1ScI (ORCPT ); Tue, 28 Apr 2020 14:32:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:48080 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729772AbgD1ScH (ORCPT ); Tue, 28 Apr 2020 14:32:07 -0400 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 331AB20B80; Tue, 28 Apr 2020 18:32:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098726; bh=eVdIKm2kuMC/roZW1kDDMJeJ4ns4NVmx3rwtzKl9sLk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BSm2oS/m8hmj5BrgdTZQIq2Ss5cofwWeBWijgG08G4qCCmkS1qQCkUR+dNt8IomZK 25b2OB6Q86kXmLvNxitQe/Rj4Iz/owMochRUJSgk8JgE6GejbCovmZ2GSos76mge/u 6jSHErqhGfrHqBnGZCIMgx4v6Tw01CUdA+vOAlto= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vasily Averin , Andrew Morton , Waiman Long , Davidlohr Bueso , Manfred Spraul , Al Viro , Ingo Molnar , NeilBrown , Peter Oberparleiter , Steven Rostedt , Linus Torvalds , Sasha Levin Subject: [PATCH 4.19 022/131] ipc/util.c: sysvipc_find_ipc() should increase position index Date: Tue, 28 Apr 2020 20:23:54 +0200 Message-Id: <20200428182227.882110386@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182224.822179290@linuxfoundation.org> References: <20200428182224.822179290@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vasily Averin [ Upstream commit 89163f93c6f969da5811af5377cc10173583123b ] If seq_file .next function does not change position index, read after some lseek can generate unexpected output. https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin Signed-off-by: Andrew Morton Acked-by: Waiman Long Cc: Davidlohr Bueso Cc: Manfred Spraul Cc: Al Viro Cc: Ingo Molnar Cc: NeilBrown Cc: Peter Oberparleiter Cc: Steven Rostedt Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- ipc/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/util.c b/ipc/util.c index 0af05752969f1..b111e792b3125 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -735,13 +735,13 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos, total++; } + *new_pos = pos + 1; if (total >= ids->in_use) return NULL; for (; pos < IPCMNI; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { - *new_pos = pos + 1; rcu_read_lock(); ipc_lock_object(ipc); return ipc; -- 2.20.1