From patchwork Mon Feb 4 20:22:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tyler Hicks X-Patchwork-Id: 1036254 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43tfKS6RRxz9sMp; Tue, 5 Feb 2019 07:23:08 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1gqklj-0003MO-Pq; Mon, 04 Feb 2019 20:23:03 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1gqkli-0003M9-Gh for kernel-team@lists.ubuntu.com; Mon, 04 Feb 2019 20:23:02 +0000 Received: from 2.general.tyhicks.us.vpn ([10.172.64.53] helo=sec.ubuntu-ci) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1gqklh-0007xg-Vu; Mon, 04 Feb 2019 20:23:02 +0000 From: Tyler Hicks To: kernel-team@lists.ubuntu.com Subject: [PATCH 1/1][SRU][C] vhost: fix OOB in get_rx_bufs() Date: Mon, 4 Feb 2019 20:22:32 +0000 Message-Id: <1549311752-18370-2-git-send-email-tyhicks@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1549311752-18370-1-git-send-email-tyhicks@canonical.com> References: <1549311752-18370-1-git-send-email-tyhicks@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Jason Wang After batched used ring updating was introduced in commit e2b3b35eb989 ("vhost_net: batch used ring update in rx"). We tend to batch heads in vq->heads for more than one packet. But the quota passed to get_rx_bufs() was not correctly limited, which can result a OOB write in vq->heads. headcount = get_rx_bufs(vq, vq->heads + nvq->done_idx, vhost_len, &in, vq_log, &log, likely(mergeable) ? UIO_MAXIOV : 1); UIO_MAXIOV was still used which is wrong since we could have batched used in vq->heads, this will cause OOB if the next buffer needs more than 960 (1024 (UIO_MAXIOV) - 64 (VHOST_NET_BATCH)) heads after we've batched 64 (VHOST_NET_BATCH) heads: Acked-by: Stefan Hajnoczi Acked-by: Kleber Sacilotto de Souza Acked-by: Stefan Bader ============================================================================= BUG kmalloc-8k (Tainted: G B ): Redzone overwritten ----------------------------------------------------------------------------- INFO: 0x00000000fd93b7a2-0x00000000f0713384. First byte 0xa9 instead of 0xcc INFO: Allocated in alloc_pd+0x22/0x60 age=3933677 cpu=2 pid=2674 kmem_cache_alloc_trace+0xbb/0x140 alloc_pd+0x22/0x60 gen8_ppgtt_create+0x11d/0x5f0 i915_ppgtt_create+0x16/0x80 i915_gem_create_context+0x248/0x390 i915_gem_context_create_ioctl+0x4b/0xe0 drm_ioctl_kernel+0xa5/0xf0 drm_ioctl+0x2ed/0x3a0 do_vfs_ioctl+0x9f/0x620 ksys_ioctl+0x6b/0x80 __x64_sys_ioctl+0x11/0x20 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 INFO: Slab 0x00000000d13e87af objects=3 used=3 fp=0x (null) flags=0x200000000010201 INFO: Object 0x0000000003278802 @offset=17064 fp=0x00000000e2e6652b Fixing this by allocating UIO_MAXIOV + VHOST_NET_BATCH iovs for vhost-net. This is done through set the limitation through vhost_dev_init(), then set_owner can allocate the number of iov in a per device manner. This fixes CVE-2018-16880. Fixes: e2b3b35eb989 ("vhost_net: batch used ring update in rx") Signed-off-by: Jason Wang Signed-off-by: David S. Miller CVE-2018-16880 (backported from commit b46a0bf78ad7b150ef5910da83859f7f5a514ffd) [tyhicks: VHOST_NET_BATCH is VHOST_RX_BATCH in Cosmic] Signed-off-by: Tyler Hicks --- drivers/vhost/net.c | 3 ++- drivers/vhost/scsi.c | 2 +- drivers/vhost/vhost.c | 7 ++++--- drivers/vhost/vhost.h | 4 +++- drivers/vhost/vsock.c | 2 +- 5 files changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 6b86ca8772fb..b72bfeda82a5 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -984,7 +984,8 @@ static int vhost_net_open(struct inode *inode, struct file *f) n->vqs[i].rx_ring = NULL; vhost_net_buf_init(&n->vqs[i].rxq); } - vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); + vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX, + UIO_MAXIOV + VHOST_RX_BATCH); vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, EPOLLOUT, dev); vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, EPOLLIN, dev); diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index fe7914dffd8f..0c3e413fe89f 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -1398,7 +1398,7 @@ static int vhost_scsi_open(struct inode *inode, struct file *f) vqs[i] = &vs->vqs[i].vq; vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick; } - vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ); + vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, UIO_MAXIOV); vhost_scsi_init_inflight(vs, NULL); diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index c4424cbd9943..cd9ff58d6470 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -389,9 +389,9 @@ static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) vq->indirect = kmalloc_array(UIO_MAXIOV, sizeof(*vq->indirect), GFP_KERNEL); - vq->log = kmalloc_array(UIO_MAXIOV, sizeof(*vq->log), + vq->log = kmalloc_array(dev->iov_limit, sizeof(*vq->log), GFP_KERNEL); - vq->heads = kmalloc_array(UIO_MAXIOV, sizeof(*vq->heads), + vq->heads = kmalloc_array(dev->iov_limit, sizeof(*vq->heads), GFP_KERNEL); if (!vq->indirect || !vq->log || !vq->heads) goto err_nomem; @@ -413,7 +413,7 @@ static void vhost_dev_free_iovecs(struct vhost_dev *dev) } void vhost_dev_init(struct vhost_dev *dev, - struct vhost_virtqueue **vqs, int nvqs) + struct vhost_virtqueue **vqs, int nvqs, int iov_limit) { struct vhost_virtqueue *vq; int i; @@ -426,6 +426,7 @@ void vhost_dev_init(struct vhost_dev *dev, dev->iotlb = NULL; dev->mm = NULL; dev->worker = NULL; + dev->iov_limit = iov_limit; init_llist_head(&dev->work_list); init_waitqueue_head(&dev->wait); INIT_LIST_HEAD(&dev->read_list); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 6c844b90a168..63f88f8e8184 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -166,9 +166,11 @@ struct vhost_dev { struct list_head read_list; struct list_head pending_list; wait_queue_head_t wait; + int iov_limit; }; -void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); +void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, + int nvqs, int iov_limit); long vhost_dev_set_owner(struct vhost_dev *dev); bool vhost_dev_has_owner(struct vhost_dev *dev); long vhost_dev_check_owner(struct vhost_dev *); diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index d27d7e9b2a9e..379d6571ed4c 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -531,7 +531,7 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; - vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs)); + vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), UIO_MAXIOV); file->private_data = vsock; spin_lock_init(&vsock->send_pkt_list_lock);