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=-6.8 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 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 D5CFEC3A5A9 for ; Wed, 4 Sep 2019 20:21:12 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A9F5D2087E for ; Wed, 4 Sep 2019 20:21:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="VWSj5Kal" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A9F5D2087E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=cyphar.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HukSZZAvG4K0HREE4OcrRYH8zaQLnX7DDgp2ZqnKLV8=; b=VWSj5Kal2o4OJt sAdlrrJ9stsKmYdx8uUts2plhJihilSVJRCSBkv9TvWX1Hx3u7qaTQukANrSgZ0bUU037LPXhKOIt +M4pvYUGgauP///u3NgHvoWXIrFKmXYxiwLRGuVpRldqq3flxX1I6Ay3rvjdf4Gme74SIDsTMSteK +ymsSI8Mq1L+/tuwF/4riwTf0GCaupEbUZUE+BhL2Anlf/Eo/isdSjMvqjA6MqjkolvrGG2589Hlu 44j1pLcMFo7Sl174GiWSVyQ6qUnSuwhDDKv/gpsas8ftbmsKohbIBUVOZ4SbpfeibVtjJZCedYbVz Wpsf8M03kQ9GEEi8h3EQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i5bm8-0001f8-G4; Wed, 04 Sep 2019 20:21:08 +0000 Received: from mx2.mailbox.org ([80.241.60.215]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i5bm1-0001Zd-Q8 for linux-arm-kernel@lists.infradead.org; Wed, 04 Sep 2019 20:21:06 +0000 Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:105:465:1:2:0]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by mx2.mailbox.org (Postfix) with ESMTPS id CBDD1A11C8; Wed, 4 Sep 2019 22:20:59 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter05.heinlein-hosting.de (spamfilter05.heinlein-hosting.de [80.241.56.123]) (amavisd-new, port 10030) with ESMTP id wJ1JmQV60FQK; Wed, 4 Sep 2019 22:20:56 +0200 (CEST) From: Aleksa Sarai To: Al Viro , Jeff Layton , "J. Bruce Fields" , Arnd Bergmann , David Howells , Shuah Khan , Shuah Khan , Ingo Molnar , Peter Zijlstra , Christian Brauner Subject: [PATCH v12 03/12] sched_setattr: switch to copy_struct_{to, from}_user() Date: Thu, 5 Sep 2019 06:19:24 +1000 Message-Id: <20190904201933.10736-4-cyphar@cyphar.com> In-Reply-To: <20190904201933.10736-1-cyphar@cyphar.com> References: <20190904201933.10736-1-cyphar@cyphar.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190904_132102_308123_1311616E X-CRM114-Status: GOOD ( 17.93 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Alexander Shishkin , Rasmus Villemoes , Alexei Starovoitov , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Jiri Olsa , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Tycho Andersen , Aleksa Sarai , linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, Kees Cook , Jann Horn , linuxppc-dev@lists.ozlabs.org, Aleksa Sarai , Andy Lutomirski , Namhyung Kim , David Drysdale , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-api@vger.kernel.org, Chanho Min , Oleg Nesterov , Eric Biederman , linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds , containers@lists.linux-foundation.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org The change is very straightforward, and takes advantage of the (very minor) efficiency improvements in copy_struct_{to,from}_user() -- that the memchr_inv() check is done on a buffer instead of one-at-at-time with get_user() or put_user(). Signed-off-by: Aleksa Sarai --- kernel/sched/core.c | 85 ++++++--------------------------------------- 1 file changed, 10 insertions(+), 75 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 010d578118d6..2f58b07d3468 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4900,9 +4900,6 @@ static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *a u32 size; int ret; - if (!access_ok(uattr, SCHED_ATTR_SIZE_VER0)) - return -EFAULT; - /* Zero the full structure, so that a short copy will be nice: */ memset(attr, 0, sizeof(*attr)); @@ -4910,45 +4907,19 @@ static int sched_copy_attr(struct sched_attr __user *uattr, struct sched_attr *a if (ret) return ret; - /* Bail out on silly large: */ - if (size > PAGE_SIZE) - goto err_size; - /* ABI compatibility quirk: */ if (!size) size = SCHED_ATTR_SIZE_VER0; - if (size < SCHED_ATTR_SIZE_VER0) goto err_size; - /* - * If we're handed a bigger struct than we know of, - * ensure all the unknown bits are 0 - i.e. new - * user-space does not rely on any kernel feature - * extensions we dont know about yet. - */ - if (size > sizeof(*attr)) { - unsigned char __user *addr; - unsigned char __user *end; - unsigned char val; - - addr = (void __user *)uattr + sizeof(*attr); - end = (void __user *)uattr + size; - - for (; addr < end; addr++) { - ret = get_user(val, addr); - if (ret) - return ret; - if (val) - goto err_size; - } - size = sizeof(*attr); + ret = copy_struct_from_user(attr, sizeof(*attr), uattr, size); + if (ret) { + if (ret == -E2BIG) + goto err_size; + return ret; } - ret = copy_from_user(attr, uattr, size); - if (ret) - return -EFAULT; - if ((attr->sched_flags & SCHED_FLAG_UTIL_CLAMP) && size < SCHED_ATTR_SIZE_VER1) return -EINVAL; @@ -5105,51 +5076,15 @@ SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) return retval; } -static int sched_read_attr(struct sched_attr __user *uattr, - struct sched_attr *attr, - unsigned int usize) -{ - int ret; - - if (!access_ok(uattr, usize)) - return -EFAULT; - - /* - * If we're handed a smaller struct than we know of, - * ensure all the unknown bits are 0 - i.e. old - * user-space does not get uncomplete information. - */ - if (usize < sizeof(*attr)) { - unsigned char *addr; - unsigned char *end; - - addr = (void *)attr + usize; - end = (void *)attr + sizeof(*attr); - - for (; addr < end; addr++) { - if (*addr) - return -EFBIG; - } - - attr->size = usize; - } - - ret = copy_to_user(uattr, attr, attr->size); - if (ret) - return -EFAULT; - - return 0; -} - /** * sys_sched_getattr - similar to sched_getparam, but with sched_attr * @pid: the pid in question. * @uattr: structure containing the extended parameters. - * @size: sizeof(attr) for fwd/bwd comp. + * @usize: sizeof(attr) for fwd/bwd comp. * @flags: for future extension. */ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, - unsigned int, size, unsigned int, flags) + unsigned int, usize, unsigned int, flags) { struct sched_attr attr = { .size = sizeof(struct sched_attr), @@ -5157,8 +5092,8 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, struct task_struct *p; int retval; - if (!uattr || pid < 0 || size > PAGE_SIZE || - size < SCHED_ATTR_SIZE_VER0 || flags) + if (!uattr || pid < 0 || usize > PAGE_SIZE || + usize < SCHED_ATTR_SIZE_VER0 || flags) return -EINVAL; rcu_read_lock(); @@ -5188,7 +5123,7 @@ SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, rcu_read_unlock(); - retval = sched_read_attr(uattr, &attr, size); + retval = copy_struct_to_user(uattr, usize, &attr, sizeof(attr)); return retval; out_unlock: -- 2.23.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel