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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65489C433F5 for ; Fri, 13 May 2022 14:35:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381304AbiEMOfN (ORCPT ); Fri, 13 May 2022 10:35:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381157AbiEMObD (ORCPT ); Fri, 13 May 2022 10:31:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D71B3606F1; Fri, 13 May 2022 07:28:33 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 64A3862154; Fri, 13 May 2022 14:28:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 71CD0C34100; Fri, 13 May 2022 14:28:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1652452112; bh=4z0obWSDnb57xGzIznvmN7huABcV6pSFsAXa2Q/cy8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OsQhlVT0/ozD0omUkRGeP5HhhMDIII1KA8ZoH3AlqmSpwLEnq7RTOA/AiyRX1cwoy eAN7Bdi8C3n8e8Mo9WAVZzVMoOIpMkizjcjVbbCjx3vJjgz5Ne3xKvqkGYSIwktrJw RXUGWsIOcunVvuumn/0nMJmoSi7aTfa0+2jNkjJY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miaohe Lin , Andrew Morton , Hugh Dickins , Herbert van den Bergh , Chris Mason , Linus Torvalds Subject: [PATCH 5.15 20/21] mm/mlock: fix potential imbalanced rlimit ucounts adjustment Date: Fri, 13 May 2022 16:24:02 +0200 Message-Id: <20220513142230.458765860@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220513142229.874949670@linuxfoundation.org> References: <20220513142229.874949670@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Miaohe Lin commit 5c2a956c3eea173b2bc89f632507c0eeaebf6c4a upstream. user_shm_lock forgets to set allowed to 0 when get_ucounts fails. So the later user_shm_unlock might do the extra dec_rlimit_ucounts. Fix this by resetting allowed to 0. Link: https://lkml.kernel.org/r/20220310132417.41189-1-linmiaohe@huawei.com Fixes: d7c9e99aee48 ("Reimplement RLIMIT_MEMLOCK on top of ucounts") Signed-off-by: Miaohe Lin Reviewed-by: Andrew Morton Acked-by: Hugh Dickins Cc: Herbert van den Bergh Cc: Chris Mason Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/mlock.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/mlock.c +++ b/mm/mlock.c @@ -837,6 +837,7 @@ int user_shm_lock(size_t size, struct uc } if (!get_ucounts(ucounts)) { dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); + allowed = 0; goto out; } allowed = 1;