From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.215.178 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793845938; b=haJwfjYPnQIsdDvYr75STQcZQDQbiXD8oE4K5YYv4vdSeZq+r0bMfkc/KFtc46pFDUHs cItBj2G4Egz8iVDWsX+8msMgzhX9pZ+bsFUzEzBhS5Q6zAeC30NcLimscHFN+3187lZCB /R45dezQLhXDTDAKMt4q1gpH4+Rg8xJkgPRS2Qc4ttF9LYGp/DMQ5WZEWYwromrZo9pZb PVpriWAezsoVVkQ5P4LJXzMS17dCOWz652osmz63LgWwXx5HS9WGXPttOmlEzDNJYyip9 H650sg2v5DUz4ScQTomc5TJc//VFanBAR9iqvkLgZh5wl+aZMox9fyaQ4eR95caM2vw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793845938; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Transfer-Encoding; bh=wN53f2o2lrw0Ep6vBL4s/UvXzf4wV7yzLC3X+qzVNBI=; b=qdE2nC4whuYs/OCj1uXM7avK/hmiWUC/ScjipmrwnLVLx5aZC27SYdAu3mEtyuqXFJtV Yu6GX+1qx/JEHPlTtP8GdfqWvN64DZT9VA20HIY6WwJ7NizZH6g4XVufYVGVzYYgVFQUd bAWy2dwp6JOX5aN8PcS4fmumnDeqZfm2f0EFxL81Koarvi/LsQHmAJeDf5ubC0+LnQqfi 21Pq256RJJbBp+MzwfPDhDS/g6tXhhjuLZCMQiH58WlaL0LxnQ+6Zm+bJiM6qbBGOi3OT YbFGjG+ZV8nmKuEUk5ZwqCr0Mec4N+yH6kwT/PPnrdDiJwc7v8P3mpFpTErVhWpF+aQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=Z9UCIuO0; arc=none smtp.remote-ip=209.85.215.178 Received: from mail-pg1-f178.google.com (mail-pg1-f178.google.com [209.85.215.178]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 280B9606D809 for ; Thu, 5 Nov 2026 02:32:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 280B9606D809 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=Z9UCIuO0 Received: by mail-pg1-f178.google.com with SMTP id 41be03b00d2f7-cc502d509c0so579364a12.2 for ; Wed, 04 Nov 2026 18:32:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1793845936; x=1794450736; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=wN53f2o2lrw0Ep6vBL4s/UvXzf4wV7yzLC3X+qzVNBI=; b=Z9UCIuO0F9KtFmLbkWcijfRaMi6XgRTdK+gwkr+KKxwQkLPikMroj/8ImiGeWNskcu 5OXUwAZfjxPP3G2mzgeWEhfDsr++ZSXJ4RXFzC8Hi+5RNQgXC9Mx529OROEZ0trXWY2Z wIHzLHTDQJxeWB6T7KlxJ7AYhP1j0pF0wgLW7iGyKOUAPAosamETz9q8hRGOozJrWmAn cmQIDl61Mgw7OH7SoG754IM6a0wa8EwLRM5tvzODq8XZsyBjgyQcjSgXmyklZcv708pY nAoQKgf4Q2lLo3WSYnZA7SkFHXHNK8lDjawOjX8LgGf9umGuthjPKXEAu5G0AvkLUjfP Hb3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793845936; x=1794450736; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=wN53f2o2lrw0Ep6vBL4s/UvXzf4wV7yzLC3X+qzVNBI=; b=QMvEnXTa7cns7QLLHmN/pUPv5Xh0q6jHUD8CVAJhcnjbPIdgzs3JYGTMAPsUDKav3w lBCck0xfVmmchk6t9T/1uSJ1s+z5eJ+gQ1AuWzgLCihKuIP4N6/4fnOYa1DfP6tOp4CU i+OzCZmkVQ6qKlmK226nTNdipfP5x9Naqt46cUWCL0kn/1PoPUaRJi2ongw+l+Ai7Etq CwOvBdiSsYfX1B9oRe4jJ+6Yu84wr5+FygjCG9VySTcQlni4bEALXxlqgsj/DQ70w5ji 6KNswQQBFUTK18hh3Cc7H3nqm4EI+pJCjSkc8eFDqSal9i2NY7GHvZVof8LyDJ87Y9lW IMJQ== X-Forwarded-Encrypted: i=1; AKwUvBxzYlbyKQL1PGIRCAi5F7yrdcuaxHMqSdafuQVGVwjJRIB81n1HOpdowNYMWeOID1hwX98cK0nVyzg9LTk=@vger.kernel.org X-Gm-Message-State: APuU4Z8YZhw0XXIqM0XaE2TQfztV0beoqo+Xpem9NT2qNfdHqmFX/cto EKPOKSauxQM5Ox2du223lFvG0vlGqI+ugklg7cxXiPDjYnWQs3D33w7O X-Gm-Gg: AYBFou1RUj1L4NQKCVde2bIKuI4sKlGdTO8jR99Sd1IVvBNdyNnVLGQvseh7owSHuJ1 hAOgsoDoZr1kd/iLyZEJOoE3UdrvzMqhZRWsZDYdcb5y8sulLY3KyHoNvjhT44PckTbMUqe6x4t 4Moo0H1AnaWU6XF1HGJOOBqUYOu+KivjsaLOLZAAbxoAIBRNybz5SGwGFx7UmL8SlhYq5GFJ/st RtALmfp/tOUvutbz75QtUcBSq/HHG7nTq1UMRGxZ0RkRXrfZwr2R+I9I4y4ylR+bpyl2yDsp5rq y6lraBz77CFsfbYc1PmM2/sQyGsyLNj9j1Rw32VQyPFq3oAFTzhtHmq6E9lJOvJhTUyv58uNCTF GmUnjk7XWjyxOSsAyACWPPudxyh7ogVx+KJeXzZKlL5ZXb85oeBdZBikMfcM8zJt2HgXXBMkWqO YVGQ3lMsaf/KrMrPKmvoJBEWdBHjyx1OBHkpQt36YT6HHeNwERyzi/Hd2cQzZLppMd7BF9nuZxP C2R666QLFHX8BSD3dqlWjosDGgjy571t12N28GQVFQWKeyoH9i1KFilm7zrB2LKxoOySusTFfC2 LSuNaLpJj7iaf2e0BjcwEakIu79pEF4Q4CiUnwWACsg+WAfcAqFvLq0F/dzXGexetHsVZlPCVRm Bz+IkgQhB+nyTNcOF6WwzieNYnfGbvw9Xl291yVt92vppdwg= X-Received: by 2002:a17:90b:4ac1:b0:3a8:211b:6c6f with SMTP id 98e67ed59e1d1-3ae898662b7mr16216560a91.67.1793845936369; Wed, 04 Nov 2026 18:32:16 -0800 (PST) Received: from localhost.localdomain ([183.96.175.225]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3b0b323cd3csm1292775a91.3.2026.11.04.18.32.13 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Wed, 04 Nov 2026 18:32:15 -0800 (PST) From: Joonho Lee To: linux-sound@vger.kernel.org Cc: tiwai@suse.com, perex@perex.cz, anton.yakovlev@opensynergy.com, mst@redhat.com, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, corbet@lwn.net, skhan@linuxfoundation.org, rdunlap@infradead.org, linux-doc@vger.kernel.org, Joonho Lee Subject: [PATCH v16 08/12] ALSA: virtio: Keep control payloads alive through DMA completion Date: Thu, 5 Nov 2026 11:31:36 +0900 Message-ID: <20261105023140.18373-9-mynameisjune111@gmail.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20261105023140.18373-1-mynameisjune111@gmail.com> References: <20261105023140.18373-1-mynameisjune111@gmail.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Control requests can expose caller-owned payloads to the device after a synchronous send times out. Keep request and response headers and payloads in the reference-counted message so caller cleanup cannot invalidate DMA. Keep the queue reference until device completion or post-reset cleanup, even when the caller times out or is interrupted. Consume the caller's reference on every send path, and let response readers retain an extra reference through copyout. Check payload sizes and allocation arithmetic before building the scatterlists. A control value payload is also read by the CPU as a typed structure. DMA cacheline alignment alone does not guarantee the structure's CPU alignment. Align regions to the greater of the DMA cacheline and control-value type alignment, and reserve prefix slack from the buffer base so typed accesses remain aligned while scatterlist regions stay on cacheline boundaries. Keep response values in a separately allocated aligned response buffer so INTEGER64 control accesses are aligned from this patch onward. Fixes: 9d45e514da88 ("ALSA: virtio: handling control messages") Assisted-by: LLM Signed-off-by: Joonho Lee --- sound/virtio/virtio_ctl_msg.c | 289 +++++++++++++++++++++++++++++++---------- sound/virtio/virtio_ctl_msg.h | 24 ++- sound/virtio/virtio_kctl.c | 121 +++++++++-------- sound/virtio/virtio_pcm_msg.c | 2 4 files changed, 300 insertions(+), 136 deletions(-) diff --git a/sound/virtio/virtio_ctl_msg.c b/sound/virtio/virtio_ctl_msg.c --- a/sound/virtio/virtio_ctl_msg.c +++ b/sound/virtio/virtio_ctl_msg.c @@ -3,7 +3,10 @@ * virtio-snd: Virtio sound device * Copyright (C) 2021 OpenSynergy GmbH */ +#include +#include #include +#include #include #include "virtio_card.h" @@ -11,7 +14,12 @@ /** * struct virtio_snd_msg - Control message. * @sg_request: Scattergather list containing a device request (header). + * @sg_request_data: Scattergather list containing request data. * @sg_response: Scattergather list containing a device response (status). + * @sg_response_data: Scattergather list containing response data. + * @dma_buffer: Message-owned storage for all DMA-visible SG regions. + * @request_data_size: Size of the request data buffer. + * @response_data_size: Size of the response data buffer. * @list: Pending message list entry. * @notify: Request completed notification. * @ref_count: Reference count used to manage a message lifetime. @@ -19,7 +27,12 @@ */ struct virtio_snd_msg { struct scatterlist sg_request; + struct scatterlist sg_request_data; struct scatterlist sg_response; + struct scatterlist sg_response_data; + void *dma_buffer; + size_t request_data_size; + size_t response_data_size; struct list_head list; struct completion notify; refcount_t ref_count; @@ -47,8 +60,10 @@ */ void virtsnd_ctl_msg_unref(struct virtio_snd_msg *msg) { - if (refcount_dec_and_test(&msg->ref_count)) + if (refcount_dec_and_test(&msg->ref_count)) { + kfree(msg->dma_buffer); kfree(msg); + } } /** @@ -71,12 +86,73 @@ void *virtsnd_ctl_msg_response(struct virtio_snd_msg *msg) { return sg_virt(&msg->sg_response); +} + +/** + * virtsnd_ctl_msg_request_data() - Get the request data buffer. + * @msg: Control message. + * + * Context: Any context. + */ +void *virtsnd_ctl_msg_request_data(struct virtio_snd_msg *msg) +{ + return msg->request_data_size ? sg_virt(&msg->sg_request_data) : NULL; +} + +/** + * virtsnd_ctl_msg_response_data() - Get the response data buffer. + * @msg: Control message. + * + * Context: Any context. + */ +void *virtsnd_ctl_msg_response_data(struct virtio_snd_msg *msg) +{ + return msg->response_data_size ? sg_virt(&msg->sg_response_data) : NULL; +} + +/** + * virtsnd_ctl_msg_sg_init() - Place one DMA region on cacheline boundaries. + * @sg: Scattergather entry for the region. + * @cursor: Current location in the message-owned DMA buffer. + * @size: Region length. + * @alignment: Alignment for DMA cachelines and typed CPU accesses. + * + * Context: Any context during message allocation. + * Return: 0 on success, -EOVERFLOW if the address cannot be represented. + */ +static int virtsnd_ctl_msg_sg_init(struct scatterlist *sg, u8 **cursor, + size_t size, size_t alignment) +{ + uintptr_t address = (uintptr_t)*cursor; + uintptr_t end; + size_t padding; + + padding = address % alignment; + if (padding && + check_add_overflow(address, (uintptr_t)(alignment - padding), + &address)) + return -EOVERFLOW; + + if (check_add_overflow(address, (uintptr_t)size, &end)) + return -EOVERFLOW; + + padding = end % alignment; + if (padding && + check_add_overflow(end, (uintptr_t)(alignment - padding), &end)) + return -EOVERFLOW; + + sg_init_one(sg, (void *)address, (unsigned int)size); + *cursor = (u8 *)end; + + return 0; } /** * virtsnd_ctl_msg_alloc() - Allocate and initialize a control message. * @request_size: Size of request header. * @response_size: Size of response header. + * @request_data_size: Size of request data buffer. + * @response_data_size: Size of response data buffer. * @gfp: Kernel flags for memory allocation. * * The message will be automatically freed when the ref_count value is 0. @@ -85,20 +161,85 @@ * Return: Allocated message on success, NULL on failure. */ struct virtio_snd_msg *virtsnd_ctl_msg_alloc(size_t request_size, - size_t response_size, gfp_t gfp) + size_t response_size, + size_t request_data_size, + size_t response_data_size, + gfp_t gfp) { struct virtio_snd_msg *msg; - - if (!request_size || !response_size) + struct scatterlist *sgs[4]; + size_t sizes[4] = { + request_size, + response_size, + request_data_size, + response_data_size, + }; + size_t alignment; + size_t dma_buffer_size; + size_t aligned_size; + size_t padding; + u8 *data; + unsigned int i; + int cache_alignment; + int rc; + + if (!request_size || !response_size || request_size > UINT_MAX || + response_size > UINT_MAX || request_data_size > UINT_MAX || + response_data_size > UINT_MAX) return NULL; - - msg = kzalloc(sizeof(*msg) + request_size + response_size, gfp); + cache_alignment = dma_get_cache_alignment(); + if (cache_alignment <= 0) + return NULL; + /* DMA coherence does not remove the CPU's type alignment requirement. */ + alignment = max_t(size_t, cache_alignment, + __alignof__(struct virtio_snd_ctl_value)); + + /* Reserve prefix alignment slack before the first DMA region. */ + dma_buffer_size = alignment - 1; + for (i = 0; i < ARRAY_SIZE(sizes); ++i) { + if (!sizes[i]) + continue; + + padding = sizes[i] % alignment; + aligned_size = sizes[i]; + if (padding && + check_add_overflow(aligned_size, alignment - padding, + &aligned_size)) + return NULL; + + if (check_add_overflow(dma_buffer_size, aligned_size, + &dma_buffer_size)) + return NULL; + } + + msg = kzalloc(sizeof(*msg), gfp); if (!msg) return NULL; - sg_init_one(&msg->sg_request, (u8 *)msg + sizeof(*msg), request_size); - sg_init_one(&msg->sg_response, (u8 *)msg + sizeof(*msg) + request_size, - response_size); + msg->dma_buffer = kzalloc(dma_buffer_size, gfp); + if (!msg->dma_buffer) { + kfree(msg); + return NULL; + } + data = msg->dma_buffer; + sgs[0] = &msg->sg_request; + sgs[1] = &msg->sg_response; + sgs[2] = &msg->sg_request_data; + sgs[3] = &msg->sg_response_data; + for (i = 0; i < ARRAY_SIZE(sizes); ++i) { + if (!sizes[i]) + continue; + + rc = virtsnd_ctl_msg_sg_init(sgs[i], &data, sizes[i], alignment); + if (rc) { + kfree(msg->dma_buffer); + kfree(msg); + return NULL; + } + } + + msg->request_data_size = request_data_size; + msg->response_data_size = response_data_size; INIT_LIST_HEAD(&msg->list); init_completion(&msg->notify); @@ -112,17 +253,15 @@ * virtsnd_ctl_msg_send() - Send a control message. * @snd: VirtIO sound device. * @msg: Control message. - * @out_sgs: Additional sg-list to attach to the request header (may be NULL). - * @in_sgs: Additional sg-list to attach to the response header (may be NULL). * @nowait: Flag indicating whether to wait for completion. * * Context: Any context. Takes and releases the control queue spinlock. * May sleep if @nowait is false. + * Consumes the caller's reference on every return path. * Return: 0 on success, -errno on failure. */ int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg, - struct scatterlist *out_sgs, - struct scatterlist *in_sgs, bool nowait) + bool nowait) { struct virtio_device *vdev = snd->vdev; struct virtio_snd_queue *queue = virtsnd_control_queue(snd); @@ -133,6 +272,7 @@ unsigned int nins = 0; struct scatterlist *psgs[4]; bool notify = false; + unsigned long flags; int rc; virtsnd_ctl_msg_ref(msg); @@ -142,27 +282,27 @@ response->code = cpu_to_le32(VIRTIO_SND_S_IO_ERR); psgs[nouts++] = &msg->sg_request; - if (out_sgs) - psgs[nouts++] = out_sgs; + if (msg->request_data_size) + psgs[nouts++] = &msg->sg_request_data; psgs[nouts + nins++] = &msg->sg_response; - if (in_sgs) - psgs[nouts + nins++] = in_sgs; - - scoped_guard(spinlock_irqsave, &queue->lock) { - if (snd->ctl_msgs_blocked) - rc = -ENODEV; - else - rc = virtqueue_add_sgs(queue->vqueue, psgs, nouts, nins, - msg, GFP_ATOMIC); - if (!rc) { - notify = virtqueue_kick_prepare(queue->vqueue); - - list_add_tail(&msg->list, &snd->ctl_msgs); - if (notify) - virtqueue_notify(queue->vqueue); - } - } + if (msg->response_data_size) + psgs[nouts + nins++] = &msg->sg_response_data; + + spin_lock_irqsave(&queue->lock, flags); + if (snd->ctl_msgs_blocked) + rc = -ENODEV; + else + rc = virtqueue_add_sgs(queue->vqueue, psgs, nouts, nins, msg, + GFP_ATOMIC); + if (!rc) { + notify = virtqueue_kick_prepare(queue->vqueue); + + list_add_tail(&msg->list, &snd->ctl_msgs); + if (notify) + virtqueue_notify(queue->vqueue); + } + spin_unlock_irqrestore(&queue->lock, flags); if (rc) { dev_err(&vdev->dev, "failed to send control message (0x%08x)\n", @@ -173,46 +313,36 @@ * called, it is necessary to decrement the reference count. */ virtsnd_ctl_msg_unref(msg); - - goto on_exit; - } - - if (nowait) - goto on_exit; - - rc = wait_for_completion_interruptible_timeout(&msg->notify, js); - if (rc <= 0) { + } else if (!nowait) { + rc = wait_for_completion_interruptible_timeout(&msg->notify, js); if (!rc) { dev_err(&vdev->dev, "control message (0x%08x) timeout\n", le32_to_cpu(request->code)); rc = -ETIMEDOUT; + } else if (rc > 0) { + if (READ_ONCE(msg->cancelled)) { + rc = -ENODEV; + } else { + switch (le32_to_cpu(response->code)) { + case VIRTIO_SND_S_OK: + rc = 0; + break; + case VIRTIO_SND_S_NOT_SUPP: + rc = -EOPNOTSUPP; + break; + case VIRTIO_SND_S_IO_ERR: + rc = -EIO; + break; + default: + rc = -EINVAL; + break; + } + } } - - goto on_exit; - } - - if (READ_ONCE(msg->cancelled)) { - rc = -ENODEV; - goto on_exit; - } - - switch (le32_to_cpu(response->code)) { - case VIRTIO_SND_S_OK: - rc = 0; - break; - case VIRTIO_SND_S_NOT_SUPP: - rc = -EOPNOTSUPP; - break; - case VIRTIO_SND_S_IO_ERR: - rc = -EIO; - break; - default: - rc = -EINVAL; - break; - } - -on_exit: + } + + /* Drop the reference consumed by this send attempt. */ virtsnd_ctl_msg_unref(msg); return rc; @@ -308,10 +438,23 @@ { struct virtio_snd_msg *msg; struct virtio_snd_query_info *query; - struct scatterlist sg; + size_t info_size; + int rc; + + if (count < 0) + return -EINVAL; + + if (size > UINT_MAX || + check_mul_overflow((size_t)count, size, &info_size) || + info_size > UINT_MAX) + return -EOVERFLOW; + + if (info_size && !info) + return -EINVAL; msg = virtsnd_ctl_msg_alloc(sizeof(*query), - sizeof(struct virtio_snd_hdr), GFP_KERNEL); + sizeof(struct virtio_snd_hdr), 0, info_size, + GFP_KERNEL); if (!msg) return -ENOMEM; @@ -321,9 +464,13 @@ query->count = cpu_to_le32(count); query->size = cpu_to_le32(size); - sg_init_one(&sg, info, count * size); - - return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false); + virtsnd_ctl_msg_ref(msg); + rc = virtsnd_ctl_msg_send(snd, msg, false); + if (!rc && info_size) + memcpy(info, virtsnd_ctl_msg_response_data(msg), info_size); + virtsnd_ctl_msg_unref(msg); + + return rc; } /** diff --git a/sound/virtio/virtio_ctl_msg.h b/sound/virtio/virtio_ctl_msg.h --- a/sound/virtio/virtio_ctl_msg.h +++ b/sound/virtio/virtio_ctl_msg.h @@ -21,20 +21,28 @@ void *virtsnd_ctl_msg_response(struct virtio_snd_msg *msg); struct virtio_snd_msg *virtsnd_ctl_msg_alloc(size_t request_size, - size_t response_size, gfp_t gfp); + size_t response_size, + size_t request_data_size, + size_t response_data_size, + gfp_t gfp); + +void *virtsnd_ctl_msg_request_data(struct virtio_snd_msg *msg); + +void *virtsnd_ctl_msg_response_data(struct virtio_snd_msg *msg); int virtsnd_ctl_msg_send(struct virtio_snd *snd, struct virtio_snd_msg *msg, - struct scatterlist *out_sgs, - struct scatterlist *in_sgs, bool nowait); + bool nowait); /** * virtsnd_ctl_msg_send_sync() - Simplified sending of synchronous message. * @snd: VirtIO sound device. * @msg: Control message. * - * After returning from this function, the message will be deleted. If message - * content is still needed, the caller must additionally to - * virtsnd_ctl_msg_ref/unref() it. + * This function consumes the caller's message reference on return. A message + * accepted by the control queue keeps its queue reference until completion or + * post-reset cleanup, including when this function returns on timeout or + * interruption. Callers that read the response after success must retain an + * additional reference through that access. * * The msg_timeout_ms module parameter defines the message completion timeout. * If the message is not completed within this time, the function will return an @@ -49,7 +57,7 @@ static inline int virtsnd_ctl_msg_send_sync(struct virtio_snd *snd, struct virtio_snd_msg *msg) { - return virtsnd_ctl_msg_send(snd, msg, NULL, NULL, false); + return virtsnd_ctl_msg_send(snd, msg, false); } /** @@ -63,7 +71,7 @@ static inline int virtsnd_ctl_msg_send_async(struct virtio_snd *snd, struct virtio_snd_msg *msg) { - return virtsnd_ctl_msg_send(snd, msg, NULL, NULL, true); + return virtsnd_ctl_msg_send(snd, msg, true); } void virtsnd_ctl_msg_cancel_all(struct virtio_snd *snd); diff --git a/sound/virtio/virtio_kctl.c b/sound/virtio/virtio_kctl.c --- a/sound/virtio/virtio_kctl.c +++ b/sound/virtio/virtio_kctl.c @@ -3,8 +3,10 @@ * virtio-snd: Virtio sound device * Copyright (C) 2022 OpenSynergy GmbH */ +#include +#include +#include #include -#include #include "virtio_card.h" @@ -157,14 +159,16 @@ struct virtio_snd_ctl_hdr *hdr; struct virtio_snd_ctl_value *kvalue; size_t request_size = sizeof(*hdr); - size_t response_size = sizeof(struct virtio_snd_hdr) + sizeof(*kvalue); + size_t response_size = sizeof(struct virtio_snd_hdr); unsigned int i; int rc; - msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL); + msg = virtsnd_ctl_msg_alloc(request_size, response_size, 0, + sizeof(*kvalue), GFP_KERNEL); if (!msg) return -ENOMEM; + /* Response lifetime through ALSA value copyout. */ virtsnd_ctl_msg_ref(msg); hdr = virtsnd_ctl_msg_request(msg); @@ -175,8 +179,7 @@ if (rc) goto on_failure; - kvalue = (void *)((u8 *)virtsnd_ctl_msg_response(msg) + - sizeof(struct virtio_snd_hdr)); + kvalue = virtsnd_ctl_msg_response_data(msg); switch (type) { case VIRTIO_SND_CTL_TYPE_BOOLEAN: @@ -233,7 +236,8 @@ size_t response_size = sizeof(struct virtio_snd_hdr); unsigned int i; - msg = virtsnd_ctl_msg_alloc(request_size, response_size, GFP_KERNEL); + msg = virtsnd_ctl_msg_alloc(request_size, response_size, 0, 0, + GFP_KERNEL); if (!msg) return -ENOMEM; @@ -288,22 +292,27 @@ struct virtio_snd *snd = snd_kcontrol_chip(kcontrol); struct virtio_snd_msg *msg; struct virtio_snd_ctl_hdr *hdr; - unsigned int *tlv; - struct scatterlist sg; + size_t request_data_size = 0; + size_t response_data_size = 0; int rc; + switch (op_flag) { + case SNDRV_CTL_TLV_OP_READ: + response_data_size = size; + break; + case SNDRV_CTL_TLV_OP_WRITE: + case SNDRV_CTL_TLV_OP_CMD: + request_data_size = size; + break; + default: + return -EINVAL; + } + msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), sizeof(struct virtio_snd_hdr), + request_data_size, response_data_size, GFP_KERNEL); if (!msg) return -ENOMEM; - - tlv = kzalloc(size, GFP_KERNEL); - if (!tlv) { - rc = -ENOMEM; - goto on_msg_unref; - } - - sg_init_one(&sg, tlv, size); hdr = virtsnd_ctl_msg_request(msg); hdr->control_id = cpu_to_le32(kcontrol->private_value); @@ -312,13 +321,16 @@ case SNDRV_CTL_TLV_OP_READ: hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_READ); - rc = virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false); - if (!rc) { - if (copy_to_user(utlv, tlv, size)) - rc = -EFAULT; - } - - break; + /* Response lifetime through user copyout. */ + virtsnd_ctl_msg_ref(msg); + rc = virtsnd_ctl_msg_send(snd, msg, false); + if (!rc && size && + copy_to_user(utlv, virtsnd_ctl_msg_response_data(msg), + size)) + rc = -EFAULT; + virtsnd_ctl_msg_unref(msg); + + return rc; case SNDRV_CTL_TLV_OP_WRITE: case SNDRV_CTL_TLV_OP_CMD: if (op_flag == SNDRV_CTL_TLV_OP_WRITE) @@ -327,28 +339,16 @@ hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_TLV_COMMAND); - if (copy_from_user(tlv, utlv, size)) { - rc = -EFAULT; - goto on_msg_unref; - } else { - rc = virtsnd_ctl_msg_send(snd, msg, &sg, NULL, false); + if (size && copy_from_user(virtsnd_ctl_msg_request_data(msg), utlv, + size)) { + virtsnd_ctl_msg_unref(msg); + return -EFAULT; } - break; - default: - rc = -EINVAL; - /* We never get here - we listed all values for op_flag */ - WARN_ON(1); - goto on_msg_unref; - } - kfree(tlv); - return rc; - -on_msg_unref: - virtsnd_ctl_msg_unref(msg); - kfree(tlv); - - return rc; + return virtsnd_ctl_msg_send(snd, msg, false); + } + + return -EINVAL; } /** @@ -369,27 +369,36 @@ struct virtio_snd_msg *msg; struct virtio_snd_ctl_hdr *hdr; unsigned int n = le32_to_cpu(kinfo->value.enumerated.items); - struct scatterlist sg; - - msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), - sizeof(struct virtio_snd_hdr), GFP_KERNEL); - if (!msg) - return -ENOMEM; + size_t items_size; + int rc; + + if (check_mul_overflow((size_t)n, sizeof(*kctl->items), &items_size) || + items_size > UINT_MAX) + return -EOVERFLOW; kctl->items = devm_kcalloc(&vdev->dev, n, sizeof(*kctl->items), GFP_KERNEL); - if (!kctl->items) { - virtsnd_ctl_msg_unref(msg); - return -ENOMEM; - } - - sg_init_one(&sg, kctl->items, n * sizeof(*kctl->items)); + if (!kctl->items) + return -ENOMEM; + + msg = virtsnd_ctl_msg_alloc(sizeof(*hdr), + sizeof(struct virtio_snd_hdr), 0, items_size, + GFP_KERNEL); + if (!msg) + return -ENOMEM; hdr = virtsnd_ctl_msg_request(msg); hdr->hdr.code = cpu_to_le32(VIRTIO_SND_R_CTL_ENUM_ITEMS); hdr->control_id = cpu_to_le32(cid); - return virtsnd_ctl_msg_send(snd, msg, NULL, &sg, false); + /* Item-buffer lifetime through the control-list copyout. */ + virtsnd_ctl_msg_ref(msg); + rc = virtsnd_ctl_msg_send(snd, msg, false); + if (!rc && items_size) + memcpy(kctl->items, virtsnd_ctl_msg_response_data(msg), items_size); + virtsnd_ctl_msg_unref(msg); + + return rc; } /** diff --git a/sound/virtio/virtio_pcm_msg.c b/sound/virtio/virtio_pcm_msg.c --- a/sound/virtio/virtio_pcm_msg.c +++ b/sound/virtio/virtio_pcm_msg.c @@ -687,7 +687,7 @@ break; } - msg = virtsnd_ctl_msg_alloc(request_size, response_size, gfp); + msg = virtsnd_ctl_msg_alloc(request_size, response_size, 0, 0, gfp); if (msg) { struct virtio_snd_pcm_hdr *hdr = virtsnd_ctl_msg_request(msg);