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=-12.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 59F1BC433EA for ; Tue, 28 Jul 2020 16:38:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36CE22053B for ; Tue, 28 Jul 2020 16:38:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="vUJeEAPm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731729AbgG1Qiz (ORCPT ); Tue, 28 Jul 2020 12:38:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731367AbgG1Qis (ORCPT ); Tue, 28 Jul 2020 12:38:48 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A4F31C061794 for ; Tue, 28 Jul 2020 09:38:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=38yhl6z8pLkoujYyYs/iGNy1UHgim84K0vplDqKrRRg=; b=vUJeEAPmVI2lRPiH0UP/VBlNxZ OmlK/KxePCcWzxK7fknk7UJkDOeQiOCeatSRtmFtrZ6+VDUAasyW8KwDKTQRP5ORKA6GdO+hRoTKy aWUwNRCcywtHZYMu64Eqhrz6a2xttEER3usg4WMWqedABjk7iHYIyNLsQMQQuRDG2c3UFdhjypuS/ Sof3gnqkkXdGXva+OEuMIxPdRuDmqg5UXlJCQ6rDsgpFpu0750dzqa2hLg1fwi1Vy9haFyXC/tiOm JLKMIDuQ1cIvI+vJ1lyoQWt/OIV0Inf6d09zbapRWAR8hnHituls3K/uXRKDQxP65JFeOni/8njx+ gZYusOsA==; Received: from [2001:4bb8:180:6102:fd04:50d8:4827:5508] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1k0Scl-0007Wq-Ck; Tue, 28 Jul 2020 16:38:43 +0000 From: Christoph Hellwig To: "David S. Miller" Cc: Jan Engelhardt , Ido Schimmel , "Jason A. Donenfeld" , David Laight , netdev@vger.kernel.org Subject: [PATCH 4/4] net: improve the user pointer check in init_user_sockptr Date: Tue, 28 Jul 2020 18:38:36 +0200 Message-Id: <20200728163836.562074-5-hch@lst.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200728163836.562074-1-hch@lst.de> References: <20200728163836.562074-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Make sure not just the pointer itself but the whole range lies in the user address space. For that pass the length and then use the access_ok helper to do the check. Fixes: 6d04fe15f78a ("net: optimize the sockptr_t for unified kernel/user address spaces") Reported-by: David Laight Signed-off-by: Christoph Hellwig --- include/linux/sockptr.h | 18 ++++++------------ net/ipv4/bpfilter/sockopt.c | 2 +- net/socket.c | 2 +- 3 files changed, 8 insertions(+), 14 deletions(-) diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h index 9e6c81d474cba8..96840def9d69cc 100644 --- a/include/linux/sockptr.h +++ b/include/linux/sockptr.h @@ -27,14 +27,6 @@ static inline sockptr_t KERNEL_SOCKPTR(void *p) { return (sockptr_t) { .kernel = p }; } - -static inline int __must_check init_user_sockptr(sockptr_t *sp, void __user *p) -{ - if ((unsigned long)p >= TASK_SIZE) - return -EFAULT; - sp->user = p; - return 0; -} #else /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ typedef struct { union { @@ -53,14 +45,16 @@ static inline sockptr_t KERNEL_SOCKPTR(void *p) { return (sockptr_t) { .kernel = p, .is_kernel = true }; } +#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ -static inline int __must_check init_user_sockptr(sockptr_t *sp, void __user *p) +static inline int __must_check init_user_sockptr(sockptr_t *sp, void __user *p, + size_t size) { - sp->user = p; - sp->is_kernel = false; + if (!access_ok(p, size)) + return -EFAULT; + *sp = (sockptr_t) { .user = p }; return 0; } -#endif /* CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE */ static inline bool sockptr_is_null(sockptr_t sockptr) { diff --git a/net/ipv4/bpfilter/sockopt.c b/net/ipv4/bpfilter/sockopt.c index 94f18d2352d007..545b2640f0194d 100644 --- a/net/ipv4/bpfilter/sockopt.c +++ b/net/ipv4/bpfilter/sockopt.c @@ -65,7 +65,7 @@ int bpfilter_ip_get_sockopt(struct sock *sk, int optname, if (get_user(len, optlen)) return -EFAULT; - err = init_user_sockptr(&optval, user_optval); + err = init_user_sockptr(&optval, user_optval, len); if (err) return err; return bpfilter_mbox_request(sk, optname, optval, len, false); diff --git a/net/socket.c b/net/socket.c index 94ca4547cd7c53..aff52e81653ce3 100644 --- a/net/socket.c +++ b/net/socket.c @@ -2105,7 +2105,7 @@ int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval, if (optlen < 0) return -EINVAL; - err = init_user_sockptr(&optval, user_optval); + err = init_user_sockptr(&optval, user_optval, optlen); if (err) return err; -- 2.27.0