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 smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (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 9FA5AC433F5 for ; Mon, 30 May 2022 13:52:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 5024640A59; Mon, 30 May 2022 13:52:20 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HK8xymVPIMWd; Mon, 30 May 2022 13:52:19 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTPS id EDC3840191; Mon, 30 May 2022 13:52:18 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id C32B0C0039; Mon, 30 May 2022 13:52:18 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [IPv6:2605:bc80:3010::138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2CB67C002D for ; Mon, 30 May 2022 13:52:17 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 0CDF081B99 for ; Mon, 30 May 2022 13:52:17 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=kernel.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pMMO3rGZ2nPW for ; Mon, 30 May 2022 13:52:16 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by smtp1.osuosl.org (Postfix) with ESMTPS id DAD1E81B3E for ; Mon, 30 May 2022 13:52:15 +0000 (UTC) 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 2FB3060EC3; Mon, 30 May 2022 13:52:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 99750C385B8; Mon, 30 May 2022 13:52:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653918734; bh=+Zw83mbhprbhnSOioWOEg4ncO5kSDXaueMFhlxbMSE8=; h=From:To:Cc:Subject:Date:From; b=ARTSGrvwGtjiVxnP0jamSJ3cct60LgvkH+Hw644OTE62YGmG3JUVn/KjELRKx1/kn je0678pgrXWER48aEFWicZDdEyevR/hGldlO01CDkQXqJ4AKdht5d3bPX086FuuaO8 PPvXJ7NCofGLaagu0ULq4nzUu7V6Mg8vbDZ2Vw5Y/qgrE1DzLRK1I6AmidbqrGJ94m 0tbcfEPvM+hQ8MWabUx9cygxqEHYJXqC4xw6LyMh+Pm7Cx9RAJr14VFjUEbHuoxo3W RWXzkq2V4c0N9WbmTZsJIrAIHJBVi86nFBOdcYuFc80XUgt9Wh0UgRd1SlnpJzpjJr zHrJyOGjARGDg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 01/24] drm/virtio: fix NULL pointer dereference in virtio_gpu_conn_get_modes Date: Mon, 30 May 2022 09:51:48 -0400 Message-Id: <20220530135211.1937674-1-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Cc: Sasha Levin , airlied@linux.ie, Liu Zixian , dri-devel@lists.freedesktop.org, virtualization@lists.linux-foundation.org, daniel@ffwll.ch X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" From: Liu Zixian [ Upstream commit 194d250cdc4a40ccbd179afd522a9e9846957402 ] drm_cvt_mode may return NULL and we should check it. This bug is found by syzkaller: FAULT_INJECTION stacktrace: [ 168.567394] FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 1 [ 168.567403] CPU: 1 PID: 6425 Comm: syz Kdump: loaded Not tainted 4.19.90-vhulk2201.1.0.h1035.kasan.eulerosv2r10.aarch64 #1 [ 168.567406] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 [ 168.567408] Call trace: [ 168.567414] dump_backtrace+0x0/0x310 [ 168.567418] show_stack+0x28/0x38 [ 168.567423] dump_stack+0xec/0x15c [ 168.567427] should_fail+0x3ac/0x3d0 [ 168.567437] __should_failslab+0xb8/0x120 [ 168.567441] should_failslab+0x28/0xc0 [ 168.567445] kmem_cache_alloc_trace+0x50/0x640 [ 168.567454] drm_mode_create+0x40/0x90 [ 168.567458] drm_cvt_mode+0x48/0xc78 [ 168.567477] virtio_gpu_conn_get_modes+0xa8/0x140 [virtio_gpu] [ 168.567485] drm_helper_probe_single_connector_modes+0x3a4/0xd80 [ 168.567492] drm_mode_getconnector+0x2e0/0xa70 [ 168.567496] drm_ioctl_kernel+0x11c/0x1d8 [ 168.567514] drm_ioctl+0x558/0x6d0 [ 168.567522] do_vfs_ioctl+0x160/0xf30 [ 168.567525] ksys_ioctl+0x98/0xd8 [ 168.567530] __arm64_sys_ioctl+0x50/0xc8 [ 168.567536] el0_svc_common+0xc8/0x320 [ 168.567540] el0_svc_handler+0xf8/0x160 [ 168.567544] el0_svc+0x10/0x218 KASAN stacktrace: [ 168.567561] BUG: KASAN: null-ptr-deref in virtio_gpu_conn_get_modes+0xb4/0x140 [virtio_gpu] [ 168.567565] Read of size 4 at addr 0000000000000054 by task syz/6425 [ 168.567566] [ 168.567571] CPU: 1 PID: 6425 Comm: syz Kdump: loaded Not tainted 4.19.90-vhulk2201.1.0.h1035.kasan.eulerosv2r10.aarch64 #1 [ 168.567573] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 [ 168.567575] Call trace: [ 168.567578] dump_backtrace+0x0/0x310 [ 168.567582] show_stack+0x28/0x38 [ 168.567586] dump_stack+0xec/0x15c [ 168.567591] kasan_report+0x244/0x2f0 [ 168.567594] __asan_load4+0x58/0xb0 [ 168.567607] virtio_gpu_conn_get_modes+0xb4/0x140 [virtio_gpu] [ 168.567612] drm_helper_probe_single_connector_modes+0x3a4/0xd80 [ 168.567617] drm_mode_getconnector+0x2e0/0xa70 [ 168.567621] drm_ioctl_kernel+0x11c/0x1d8 [ 168.567624] drm_ioctl+0x558/0x6d0 [ 168.567628] do_vfs_ioctl+0x160/0xf30 [ 168.567632] ksys_ioctl+0x98/0xd8 [ 168.567636] __arm64_sys_ioctl+0x50/0xc8 [ 168.567641] el0_svc_common+0xc8/0x320 [ 168.567645] el0_svc_handler+0xf8/0x160 [ 168.567649] el0_svc+0x10/0x218 Signed-off-by: Liu Zixian Link: http://patchwork.freedesktop.org/patch/msgid/20220322091730.1653-1-liuzixian4@huawei.com Signed-off-by: Gerd Hoffmann Signed-off-by: Sasha Levin --- drivers/gpu/drm/virtio/virtgpu_display.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c index 58048709c34e..1e528f13959d 100644 --- a/drivers/gpu/drm/virtio/virtgpu_display.c +++ b/drivers/gpu/drm/virtio/virtgpu_display.c @@ -184,6 +184,8 @@ static int virtio_gpu_conn_get_modes(struct drm_connector *connector) DRM_DEBUG("add mode: %dx%d\n", width, height); mode = drm_cvt_mode(connector->dev, width, height, 60, false, false, false); + if (!mode) + return count; mode->type |= DRM_MODE_TYPE_PREFERRED; drm_mode_probed_add(connector, mode); count++; -- 2.35.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization