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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 57612C2D0EC for ; Fri, 10 Apr 2020 21:34:16 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1BACE20936 for ; Fri, 10 Apr 2020 21:34:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="tHHtIAmB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BACE20936 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BADE98E0086; Fri, 10 Apr 2020 17:34:15 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B37A38E0067; Fri, 10 Apr 2020 17:34:15 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A26C88E0086; Fri, 10 Apr 2020 17:34:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id 844188E0067 for ; Fri, 10 Apr 2020 17:34:15 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 471B8180AD807 for ; Fri, 10 Apr 2020 21:34:15 +0000 (UTC) X-FDA: 76693248870.12.smell58_42367969ab627 X-HE-Tag: smell58_42367969ab627 X-Filterd-Recvd-Size: 2829 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Fri, 10 Apr 2020 21:34:14 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 BF48E2087E; Fri, 10 Apr 2020 21:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586554454; bh=Ldm4wuygklZmrR97XHcGkHoEuO03imcrpTAITUTTr3s=; h=Date:From:To:Subject:In-Reply-To:From; b=tHHtIAmB4rpM7KxN5WK/cOE1sILS2uHHoIczUiHJqFmyfdaCEjCsIC5IzQ70qnMQ3 nE7WW82Ef9WFTNDjFEenwRhfrotJmn/cwpNkxFSpplYT7zAth0qbXXlZzvapAQyWJg ZyHbK3lep4dtC9kn7nyrUxcDZPC62KhB0Z+9CQxk= Date: Fri, 10 Apr 2020 14:34:13 -0700 From: Andrew Morton To: akpm@linux-foundation.org, dave@stgolabs.net, linux-mm@kvack.org, longman@redhat.com, manfred@colorfullife.com, mingo@redhat.com, mm-commits@vger.kernel.org, neilb@suse.com, oberpar@linux.ibm.com, rostedt@goodmis.org, torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, vvs@virtuozzo.com Subject: [patch 35/35] ipc/util.c: sysvipc_find_ipc() should increase position index Message-ID: <20200410213413._tpYkgUyu%akpm@linux-foundation.org> In-Reply-To: <20200410143047.bf34a933ce1affdc042c7c80@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Vasily Averin Subject: ipc/util.c: sysvipc_find_ipc() should increase position index 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 Link: http://lkml.kernel.org/r/b7a20945-e315-8bb0-21e6-3875c14a8494@virtuozzo.com Signed-off-by: Vasily Averin Acked-by: Waiman Long Cc: Davidlohr Bueso Cc: Manfred Spraul Cc: Al Viro Cc: Ingo Molnar Cc: NeilBrown Cc: Peter Oberparleiter Cc: Steven Rostedt Signed-off-by: Andrew Morton --- ipc/util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/ipc/util.c~sysvipc_find_ipc-should-increase-position-index +++ a/ipc/util.c @@ -764,13 +764,13 @@ static struct kern_ipc_perm *sysvipc_fin total++; } + *new_pos = pos + 1; if (total >= ids->in_use) return NULL; for (; pos < ipc_mni; pos++) { ipc = idr_find(&ids->ipcs_idr, pos); if (ipc != NULL) { - *new_pos = pos + 1; rcu_read_lock(); ipc_lock_object(ipc); return ipc; _