From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 61464395AF5 for ; Wed, 13 May 2026 21:41:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778708462; cv=pass; b=d5RddzBVlea+blmnC98kGy8bq7dYtPESpi3nwxDvUZigpdgLjF/DQLUtp8daY57fvKtnOFFy/547bJdfnD4XjtguH/GCi0SStUyscEVtEPLRqSl7jwmfUpGflvHmH97W9R6PsW4klGNNr6g7+lX8SPHoA6jn/Z5mDAD1KgyjxWU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778708462; c=relaxed/simple; bh=ETkiCTij01WwnFgrtIMFxbWfdrQRnRcCgmfJKkAkS3s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=BQF0Wrx0duQ5deNfhF3HRFSEUG53w4IRisbLe+QAI0ewJVw1LlOkO3EJ9E9aXbu4AxHQ3Vkl7lVxVl9N1LVMlc2BbeSATfUahkeGHxo7pSjeHtqGIHWm03J1ZL5hXabzmV+2pZbMCKEOFsrCdcIS0zZxxknPwQeojhT4HTML3zU= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b=ekRMWwLY; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=dmitry.osipenko@collabora.com header.b="ekRMWwLY" ARC-Seal: i=1; a=rsa-sha256; t=1778708450; cv=none; d=zohomail.com; s=zohoarc; b=CUCNlIDTzpC85wfIH8PeaV6qNZl70nQT0vhjX3RNxFsa/9j6wFaiRWVzoMQ2y8fIjxyqKpcVTvJIOQlHJ/S/mZENDcewi5Yr+oOaz41mrk2oYs8o1st1aJ2Hi+9B9YENA8dVYZJ9Oig+a+yXr0xT0tQx7WMatxPThPLr/gjbMjM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1778708450; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=AAfkCdUncn2lwPDL1s9t85c0zO4+110KbKaWrEKLqBg=; b=bp29dGNPOwh84pqU6Z8EkzH2Sn/3uZaCy836/fynPzy7Kr3rL1HjegCuOXS6oDXUtVs4Tw9dTRKIA68oZZzeEGXVb0+nzRtTFwc6khu1NijHsNptXAokuslwC/fJ5M7nSF+6cFvm4DOF4cw10j90rmKdO3B6oPvfNbHZVL7teDo= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=dmitry.osipenko@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1778708450; s=zohomail; d=collabora.com; i=dmitry.osipenko@collabora.com; h=Message-ID:Date:Date:MIME-Version:Subject:Subject:To:To:Cc:Cc:References:From:From:In-Reply-To:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=AAfkCdUncn2lwPDL1s9t85c0zO4+110KbKaWrEKLqBg=; b=ekRMWwLY598KP3V0fqX0v0nrmF8cXBLkDOSfLHD1KgrJ6K+HS5ElsQAzxRi6SrfL ceKzxRo7CKFOpC22dHWade5FYnkg4w0L51YymjuTsZZCie1M18wNLCuHE2dLDBvPXdI hWW8NOjosh592xr89ZGN7KOm/hhcThxgDVh423nI= Received: by mx.zohomail.com with SMTPS id 1778708446967774.4798640957364; Wed, 13 May 2026 14:40:46 -0700 (PDT) Message-ID: <82aeba42-7872-4e92-ade8-2b7b6a8a5e43@collabora.com> Date: Thu, 14 May 2026 00:40:41 +0300 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] drm/virtio: add timeout to virtqueue wait to avoid hung task To: Ryosuke Yasuoka , David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Simona Vetter Cc: dri-devel@lists.freedesktop.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, syzbot+d6dd6f86d3aaf7eebe7406e45c1c6e549453f224@syzkaller.appspotmail.com, syzbot+908bd910da5dd79b88de4cf7baf376cc873a922e@syzkaller.appspotmail.com References: <20260512-virtio-gpu_wait_event-v1-1-207eb4c1a69a@redhat.com> Content-Language: en-US From: Dmitry Osipenko In-Reply-To: <20260512-virtio-gpu_wait_event-v1-1-207eb4c1a69a@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ZohoMailClient: External Hi, On 5/12/26 11:59, Ryosuke Yasuoka wrote: > virtio_gpu_queue_ctrl_sgs() and virtio_gpu_queue_cursor() use > wait_event() without timeout when waiting for virtqueue space. If the > host device stops processing commands, these waits block indefinitely. > Since callers may hold DRM locks, this can make the entire system > unresponsive. > > Replace wait_event() with wait_event_timeout() using a 5-second timeout, > consistent with the existing timeout pattern in the driver. On timeout, > clean up and return -ENODEV, following the same error path as > drm_dev_enter() failure. > > Reported-by: syzbot+d6dd6f86d3aaf7eebe7406e45c1c6e549453f224@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?id=d6dd6f86d3aaf7eebe7406e45c1c6e549453f224 > Reported-by: syzbot+908bd910da5dd79b88de4cf7baf376cc873a922e@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?id=908bd910da5dd79b88de4cf7baf376cc873a922e > Signed-off-by: Ryosuke Yasuoka > --- > drivers/gpu/drm/virtio/virtgpu_vq.c | 20 ++++++++++++++++++-- > 1 file changed, 18 insertions(+), 2 deletions(-) If host stops processing commands, this is a problem on host side. Isn't it? -- Best regards, Dmitry