kernel/drivers/vhost, branch linux-4.16.y

vhost: fix info leak due to uninitialized memory

2018-06-25T23:54:06Z

commit 670ae9caaca467ea1bfd325cb2a5c98ba87f94ad upstream. struct vhost_msg within struct vhost_msg_node is copied to userspace. Unfortunately it turns out on 64 bit systems vhost_msg has padding after type which gcc doesn't initialize, leaking 4 uninitialized bytes to userspace. This padding also unfortunately means 32 bit users of this interface are broken on a 64 bit kernel which will need to be fixed separately. Fixes: CVE-2018-1118 Cc: stable@vger.kernel.org Reported-by: Kevin Easton Signed-off-by: Michael S. Tsirkin Reported-by: syzbot+87cfa083e727a224754b@syzkaller.appspotmail.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

vhost_net: flush batched heads before trying to busy polling

2018-06-11T20:48:19Z

[ Upstream commit f5a4941aa6d190e676065e8f4ed35999f52a01c3 ] After commit e2b3b35eb989 ("vhost_net: batch used ring update in rx"), we tend to batch updating used heads. But it doesn't flush batched heads before trying to do busy polling, this will cause vhost to wait for guest TX which waits for the used RX. Fixing by flush batched heads before busy loop. 1 byte TCP_RR performance recovers from 13107.83 to 50402.65. Fixes: e2b3b35eb989 ("vhost_net: batch used ring update in rx") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vhost: synchronize IOTLB message with dev cleanup

2018-06-11T20:48:17Z

[ Upstream commit 1b15ad683ab42a203f98b67045b40720e99d0e9a ] DaeRyong Jeong reports a race between vhost_dev_cleanup() and vhost_process_iotlb_msg(): Thread interleaving: CPU0 (vhost_process_iotlb_msg) CPU1 (vhost_dev_cleanup) (In the case of both VHOST_IOTLB_UPDATE and VHOST_IOTLB_INVALIDATE) ===== ===== vhost_umem_clean(dev->iotlb); if (!dev->iotlb) { ret = -EFAULT; break; } dev->iotlb = NULL; The reason is we don't synchronize between them, fixing by protecting vhost_process_iotlb_msg() with dev mutex. Reported-by: DaeRyong Jeong Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vhost: Fix vhost_copy_to_user()

2018-04-19T06:54:05Z

[ Upstream commit 7ced6c98c7ab7a1f6743931e28671b833af79b1e ] vhost_copy_to_user is used to copy vring used elements to userspace. We should use VHOST_ADDR_USED instead of VHOST_ADDR_DESC. Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache") Signed-off-by: Eric Auger Acked-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vhost: fix vhost_vq_access_ok() log check

2018-04-19T06:54:04Z

[ Upstream commit d14d2b78090c7de0557362b26a4ca591aa6a9faa ] Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log when IOTLB is enabled") introduced a regression. The logic was originally: if (vq->iotlb) return 1; return A && B; After the patch the short-circuit logic for A was inverted: if (A || vq->iotlb) return A; return B; This patch fixes the regression by rewriting the checks in the obvious way, no longer returning A when vq->iotlb is non-NULL (which is hard to understand). Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com Cc: Jason Wang Signed-off-by: Stefan Hajnoczi Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

vhost: validate log when IOTLB is enabled

2018-03-29T20:22:47Z

Vq log_base is the userspace address of bitmap which has nothing to do with IOTLB. So it needs to be validated unconditionally otherwise we may try use 0 as log_base which may lead to pin pages that will lead unexpected result (e.g trigger BUG_ON() in set_bit_to_user()). Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

vhost: correctly remove wait queue during poll failure

2018-03-27T17:03:18Z

We tried to remove vq poll from wait queue, but do not check whether or not it was in a list before. This will lead double free. Fixing this by switching to use vhost_poll_stop() which zeros poll->wqh after removing poll from waitqueue to make sure it won't be freed twice. Cc: Darren Kenny Reported-by: syzbot+c0272972b01b872e604a@syzkaller.appspotmail.com Fixes: 2b8b328b61c79 ("vhost_net: handle polling errors when setting backend") Signed-off-by: Jason Wang Reviewed-by: Darren Kenny Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

vhost_net: add missing lock nesting notation

2018-03-26T16:59:01Z

We try to hold TX virtqueue mutex in vhost_net_rx_peek_head_len() after RX virtqueue mutex is held in handle_rx(). This requires an appropriate lock nesting notation to calm down deadlock detector. Fixes: 0308813724606 ("vhost_net: basic polling support") Reported-by: syzbot+7f073540b1384a614e09@syzkaller.appspotmail.com Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

vhost_net: examine pointer types during un-producing

2018-03-09T17:02:59Z

After commit fc72d1d54dd9 ("tuntap: XDP transmission"), we can actually queueing XDP pointers in the pointer ring, so we should examine the pointer type before freeing the pointer. Fixes: fc72d1d54dd9 ("tuntap: XDP transmission") Reported-by: Michael S. Tsirkin Acked-by: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: David S. Miller

vhost_net: keep private_data and rx_ring synced

2018-03-09T17:02:59Z

We get pointer ring from the exported sock, this means we should keep rx_ring and vq->private synced during both vq stop and backend set, otherwise we may see stale rx_ring. Fixes: c67df11f6e480 ("vhost_net: try batch dequing from skb array") Signed-off-by: Michael S. Tsirkin Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller