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 lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E444DC56201 for ; Tue, 4 Aug 2026 19:26:59 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1wrKmk-0007CA-9H; Tue, 04 Aug 2026 15:26:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wrKmj-0007C2-Ay for qemu-devel@nongnu.org; Tue, 04 Aug 2026 15:26:45 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1wrKmh-00059d-Nz for qemu-devel@nongnu.org; Tue, 04 Aug 2026 15:26:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785871602; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JBuZeH/hyIo3fbh1PQfwbL8P51yWnlk8B0Vwt9xpvUY=; b=Wc4k592nHl0nleoT0AvvElMDeMWySidMzaQQvNbH0KN0rnDN2Dm0+RvCFFLnz2oYFu9yle caBUOHqiQVeUgd0yQu5G5Hebuf29HdSz+3/kXkJkQpntaaPNEpY/EF0SWQ3BJTyV60XHoN hnZxtZjtm8sfY9ietaSidq7Bq8fXFBE= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-640-GiRBMkbbNxmgBFjyxatTPQ-1; Tue, 04 Aug 2026 15:26:41 -0400 X-MC-Unique: GiRBMkbbNxmgBFjyxatTPQ-1 X-Mimecast-MFC-AGG-ID: GiRBMkbbNxmgBFjyxatTPQ_1785871600 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 1AED91956069; Tue, 4 Aug 2026 19:26:40 +0000 (UTC) Received: from localhost (unknown [10.44.22.2]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id A9D5130001A4; Tue, 4 Aug 2026 19:26:38 +0000 (UTC) From: =?utf-8?q?Marc-Andr=C3=A9_Lureau?= Date: Tue, 04 Aug 2026 23:21:51 +0400 Subject: [GIT PULL v2 4/9] hw/display/virtio-gpu: fix offset wraparound in scanout_blob_to_fb MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20260804-fix-v2-4-70e8fe489c9e@redhat.com> References: <20260804-fix-v2-0-70e8fe489c9e@redhat.com> In-Reply-To: <20260804-fix-v2-0-70e8fe489c9e@redhat.com> To: qemu-devel@nongnu.org Cc: stefanha@redhat.com, "Michael S. Tsirkin" , =?utf-8?q?Alex_Benn=C3=A9e?= , Akihiko Odaki , Dmitry Osipenko X-Developer-Signature: v=1; a=openpgp-sha256; l=2466; i=marcandre.lureau@redhat.com; h=from:subject:message-id; bh=FfMPC0vcyAbfCBx4BJKAkGllsY7YFmvTU8YJxb5Uii8=; b=owEBbQKS/ZANAwAKAdro4Ql1lpzlAcsmYgBqcjzUh8lofjE6WNnOeaQWHxiFv6J51SI4Q+qdj hRzR467FpuJAjMEAAEKAB0WIQSHqb2TP4fGBtJ29i3a6OEJdZac5QUCanI81AAKCRDa6OEJdZac 5ZxNEACbAeclCDWq0lgJez8AIJ9JBhmDGnxtwBYt+1nkjRpZgzb62YOaSEwtohoL2OTnoIw5zXF AxpauUrKAUNM8Z3Zzkd/Iyy/y8cCjeMtAAzNl2rCbkU0PZVFr6e52Cn/5SAOwT/IYr/PAc1qqz0 PgXMswKa4OD44+BfUw8XgOl7norvF2BxU1eckZdjaZArGnpTgCyNEVW3Znh84gUtOa9uTwugXFO izd5Kvejp7FVcQVb+dfqR8F7yQC2gdvF95lku9rSumY410/FYZJslqzdjowwVTmKdTSvPLBMSDQ bn95SyyaiAoYFBQd3l+FE/Og5YaKe1TQ3DMME49nkKG7VWy9dQ+dX/OTmYgUl65IulUJMhX5ojJ QNlY9a23bdyBaRItFYVaM44LDcvLbmHagUdWHVtCsOpSZFFd5oS7mIs8w3fKfomhZk15p8FFxzD zoJdlaPwwvmAKBiDDK61IbFhERLyMPup9mOZZdcIe+cgDWHEmspfLhtrL91y0CMsGyxOf78Zg+M /l+Juy1c0RDQv6eyXmdMkfieYxAIB0jHcGPa8kM2cbWe4RskiXLZ5GTURQ35oPy8e53egXOAvjx E6PLTv8OUpRK4FwAGhI04gVNEVZIfr2hy+01ORik58fhI1KFJFdHpg6ee+RkVhXn004gkHpdh/M NGnXo7ODaxY8TEQ== X-Developer-Key: i=marcandre.lureau@redhat.com; a=openpgp; fpr=87A9BD933F87C606D276F62DDAE8E10975969CE5 X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=marcandre.lureau@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 4 X-Spam_score: 0.4 X-Spam_bar: / X-Spam_report: (0.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.795, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org virtio_gpu_scanout_blob_to_fb() computes the framebuffer offset from guest-controlled offsets[0], r.x, r.y and stride using uint32_t arithmetic. When the sum exceeds UINT32_MAX, silent wraparound lets the guest steer the scanout to an arbitrary in-bounds region of the blob instead of the intended rectangle. Compute the offset in uint64_t, reject values exceeding UINT32_MAX (the width of fb->offset), and only store into fb->offset once both range checks pass. ("[PATCH] hw/display/virtio-gpu: Remove the bytes_pp field") Fixes: 32db3c63ae11 ("virtio-gpu: Add virtio_gpu_set_scanout_blob") Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3871 Based-on: <20260719-bpp-v1-1-9b91946d6cf3@rsg.ci.i.u-tokyo.ac.jp> Reported-by: Cyber_black Reviewed-by: Akihiko Odaki Signed-off-by: Marc-André Lureau Message-ID: <20260725122734.1775774-1-marcandre.lureau@redhat.com> --- hw/display/virtio-gpu.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c index 0206910cc377..51592b49c21e 100644 --- a/hw/display/virtio-gpu.c +++ b/hw/display/virtio-gpu.c @@ -777,7 +777,7 @@ bool virtio_gpu_scanout_blob_to_fb(struct virtio_gpu_framebuffer *fb, struct virtio_gpu_set_scanout_blob *ss, uint64_t blob_size) { - uint64_t fbend; + uint64_t fbend, offset; uint32_t bytes_pp; fb->format = virtio_gpu_get_pixman_format(ss->format); @@ -807,18 +807,20 @@ bool virtio_gpu_scanout_blob_to_fb(struct virtio_gpu_framebuffer *fb, return false; } - fb->offset = ss->offsets[0] + ss->r.x * bytes_pp + ss->r.y * fb->stride; + offset = (uint64_t)ss->offsets[0] + (uint64_t)ss->r.x * bytes_pp + + (uint64_t)ss->r.y * fb->stride; - fbend = fb->offset; - fbend += (uint64_t) fb->stride * ss->r.height; + fbend = offset + (uint64_t)fb->stride * ss->r.height; - if (fbend > blob_size) { + if (offset > UINT32_MAX || fbend > blob_size) { qemu_log_mask(LOG_GUEST_ERROR, - "%s: fb end out of range\n", + "%s: invalid fb bounds\n", __func__); return false; } + fb->offset = offset; + return true; } -- 2.55.0