From patchwork Tue Apr 17 13:10:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 10344977 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 64A6560216 for ; Tue, 17 Apr 2018 13:10:18 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 54D3720408 for ; Tue, 17 Apr 2018 13:10:18 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 49C121FFDB; Tue, 17 Apr 2018 13:10:18 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B50C6203B9 for ; Tue, 17 Apr 2018 13:10:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753244AbeDQNKQ (ORCPT ); Tue, 17 Apr 2018 09:10:16 -0400 Received: from osg.samsung.com ([64.30.133.232]:46213 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915AbeDQNKQ (ORCPT ); Tue, 17 Apr 2018 09:10:16 -0400 Received: from localhost (localhost [127.0.0.1]) by osg.samsung.com (Postfix) with ESMTP id C96F329E11; Tue, 17 Apr 2018 06:10:15 -0700 (PDT) X-Virus-Scanned: Debian amavisd-new at dev.s-opensource.com Received: from osg.samsung.com ([127.0.0.1]) by localhost (localhost [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1m2EenfNRxJj; Tue, 17 Apr 2018 06:10:14 -0700 (PDT) Received: from vento.lan (unknown [201.86.164.1]) by osg.samsung.com (Postfix) with ESMTPSA id EE25029E08; Tue, 17 Apr 2018 06:10:12 -0700 (PDT) Date: Tue, 17 Apr 2018 10:10:09 -0300 From: Mauro Carvalho Chehab To: Hans Verkuil Cc: Linux Media Mailing List , Mauro Carvalho Chehab , Sakari Ailus , Daniel Mentz , Laurent Pinchart Subject: Re: [PATCH 4/5] media: v4l2-compat-ioctl32: fix several __user annotations Message-ID: <20180417101009.71d98c63@vento.lan> In-Reply-To: <20180417100131.3add7f67@vento.lan> References: <510d0652872c612db21be8b846755f80e3cc4588.1523960171.git.mchehab@s-opensource.com> <20180417075358.61a878c8@vento.lan> <20180417100131.3add7f67@vento.lan> Organization: Samsung X-Mailer: Claws Mail 3.15.1-dirty (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Em Tue, 17 Apr 2018 10:01:31 -0300 Mauro Carvalho Chehab escreveu: > > >> ->blocks is a u32, so this should be a u32 cast as well. > > > > Be aware that the unsigned char * cast is actually a bug: it will clamp the > > u32 'blocks' value to a u8. > > > > Regards, > > > > Hans > > What about this approach (code untested)? Even better: [PATCH] media: v4l2-compat-ioctl32: simplify casts Making the cast right for get_user/put_user is not trivial, as it needs to ensure that the types are the correct ones. Improve it by using macros. PS.: Patch untested Signed-off-by: Mauro Carvalho Chehab Thanks, Mauro diff --git a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 8c05dd9660d3..d2f0268427c2 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -30,6 +30,24 @@ get_user(__assign_tmp, from) || put_user(__assign_tmp, to); \ }) +#define get_user_cast(__x, __ptr) \ +({ \ + get_user(__x, (typeof(*__ptr) __user *)(__ptr)); \ +}) + +#define put_user_force(__x, __ptr) \ +({ \ + put_user((typeof(*__x) __force *)(__x), __ptr); \ +}) + +#define assign_in_user_cast(to, from) \ +({ \ + typeof(*from) __assign_tmp; \ + \ + get_user_cast(__assign_tmp, from) || put_user(__assign_tmp, to);\ +}) + + static long native_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { long ret = -ENOIOCTLCMD; @@ -543,8 +561,7 @@ static int get_v4l2_buffer32(struct v4l2_buffer __user *p64, return -EFAULT; uplane = aux_buf; - if (put_user((__force struct v4l2_plane *)uplane, - &p64->m.planes)) + if (put_user_force(uplane, &p64->m.planes)) return -EFAULT; while (num_planes--) { @@ -682,7 +699,7 @@ static int get_v4l2_framebuffer32(struct v4l2_framebuffer __user *p64, if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || get_user(tmp, &p32->base) || - put_user((void __force *)compat_ptr(tmp), &p64->base) || + put_user_force(compat_ptr(tmp), &p64->base) || assign_in_user(&p64->capability, &p32->capability) || assign_in_user(&p64->flags, &p32->flags) || copy_in_user(&p64->fmt, &p32->fmt, sizeof(p64->fmt))) @@ -831,8 +848,7 @@ static int get_v4l2_ext_controls32(struct file *file, if (aux_space < count * sizeof(*kcontrols)) return -EFAULT; kcontrols = aux_buf; - if (put_user((__force struct v4l2_ext_control *)kcontrols, - &p64->controls)) + if (put_user_force(kcontrols, &p64->controls)) return -EFAULT; for (n = 0; n < count; n++) { @@ -898,12 +914,11 @@ static int put_v4l2_ext_controls32(struct file *file, unsigned int size = sizeof(*ucontrols); u32 id; - if (get_user(id, (unsigned int __user *)&kcontrols->id) || + if (get_user_cast(id, &kcontrols->id) || put_user(id, &ucontrols->id) || - assign_in_user(&ucontrols->size, - (unsigned int __user *)&kcontrols->size) || + assign_in_user_cast(&ucontrols->size, &kcontrols->size) || copy_in_user(&ucontrols->reserved2, - (unsigned int __user *)&kcontrols->reserved2, + (void __user *)&kcontrols->reserved2, sizeof(ucontrols->reserved2))) return -EFAULT; @@ -916,7 +931,7 @@ static int put_v4l2_ext_controls32(struct file *file, size -= sizeof(ucontrols->value64); if (copy_in_user(ucontrols, - (unsigned int __user *)kcontrols, size)) + (void __user *)kcontrols, size)) return -EFAULT; ucontrols++; @@ -970,10 +985,9 @@ static int get_v4l2_edid32(struct v4l2_edid __user *p64, if (!access_ok(VERIFY_READ, p32, sizeof(*p32)) || assign_in_user(&p64->pad, &p32->pad) || assign_in_user(&p64->start_block, &p32->start_block) || - assign_in_user(&p64->blocks, - (unsigned char __user *)&p32->blocks) || + assign_in_user_cast(&p64->blocks, &p32->blocks) || get_user(tmp, &p32->edid) || - put_user((void __force *)compat_ptr(tmp), &p64->edid) || + put_user_force(compat_ptr(tmp), &p64->edid) || copy_in_user(p64->reserved, p32->reserved, sizeof(p64->reserved))) return -EFAULT; return 0;