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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 4B506C38A29 for ; Sat, 18 Apr 2020 14:44:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1C26B22245 for ; Sat, 18 Apr 2020 14:44:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587221066; bh=MVIksO+Ihzwb/MQhxnPtAiLylvCrk8ZR2r+pMllTCrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UNhJz6kMIRjYJjnxQhjB06lyupgurJ2Ds3uNyOAL6Bf/HiK1Yb3HRq0oThsl/ktEs WQeW1xl/JVSvo6SoghPks6E71MsEl/dIkzL5cINXiwaaSdVNALaGSiBiik0r57A2vr U8Mp8vSK8krnqROulCBDGyv7Dc17GRdPBnbZOLOM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728072AbgDROoY (ORCPT ); Sat, 18 Apr 2020 10:44:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:55986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728782AbgDROoV (ORCPT ); Sat, 18 Apr 2020 10:44:21 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0D2E12224F; Sat, 18 Apr 2020 14:44:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587221060; bh=MVIksO+Ihzwb/MQhxnPtAiLylvCrk8ZR2r+pMllTCrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oFvKTzdxPu3MkPvHk0za23IiNdHJNZOVTlXjm7ifnIK1FERfHK03btla1LU8IhIHN z0s0pB6JJimMMlGX3Baalcm156BvEeTZW0QkZMf2B8BiaoNa7okkcCs/prLq1xxrmk BBDTJTm8gncV5ytf56dnhfdjg2ouEsoB4BaUvjmY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: 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 AUTOSEL 4.9 11/23] ipc/util.c: sysvipc_find_ipc() should increase position index Date: Sat, 18 Apr 2020 10:43:53 -0400 Message-Id: <20200418144405.10565-11-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200418144405.10565-1-sashal@kernel.org> References: <20200418144405.10565-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 798cad18dd878..e65ecf3ccbdab 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -751,13 +751,13 @@ 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