linux-stable.git/drivers/vhost/vhost.c, branch linux-4.17.y

vhost: reset metadata cache when initializing new IOTLB

2018-08-22T05:44:51+00:00

[ Upstream commit b13f9c6364373a1b9f71e9846dc4fb199296f926 ]

We need to reset metadata cache during new IOTLB initialization,
otherwise the stale pointers to previous IOTLB may be still accessed
which will lead a use after free.

Reported-by: syzbot+c51e6736a1bf614b3272@syzkaller.appspotmail.com
Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache")
Signed-off-by: Jason Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

vhost: fix info leak due to uninitialized memory

2018-06-25T23:51:32+00:00

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: synchronize IOTLB message with dev cleanup

2018-05-25T02:09:51+00:00

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

vhost: return bool from *_access_ok() functions

2018-04-11T14:54:06+00:00

Currently vhost *_access_ok() functions return int.  This is error-prone
because there are two popular conventions:

1. 0 means failure, 1 means success
2. -errno means failure, 0 means success

Although vhost mostly uses #1, it does not do so consistently.
umem_access_ok() uses #2.

This patch changes the return type from int to bool so that false means
failure and true means success.  This eliminates a potential source of
errors.

Suggested-by: Linus Torvalds 
Signed-off-by: Stefan Hajnoczi 
Acked-by: Michael S. Tsirkin 
Signed-off-by: David S. Miller

vhost: fix vhost_vq_access_ok() log check

2018-04-11T14:54:06+00:00

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

vhost: Fix vhost_copy_to_user()

2018-04-11T14:52:34+00:00

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

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2018-04-07T02:21:41+00:00

Pull fw_cfg, vhost updates from Michael Tsirkin:
 "This cleans up the qemu fw cfg device driver.

  On top of this, vmcore is dumped there on crash to help debugging
  with kASLR enabled.

  Also included are some fixes in vhost"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: add vsock compat ioctl
  vhost: fix vhost ioctl signature to build with clang
  fw_cfg: write vmcoreinfo details
  crash: export paddr_vmcoreinfo_note()
  fw_cfg: add DMA register
  fw_cfg: add a public uapi header
  fw_cfg: handle fw_cfg_read_blob() error
  fw_cfg: remove inline from fw_cfg_read_blob()
  fw_cfg: fix sparse warnings around FW_CFG_FILE_DIR read
  fw_cfg: fix sparse warning reading FW_CFG_ID
  fw_cfg: fix sparse warnings with fw_cfg_file
  fw_cfg: fix sparse warnings in fw_cfg_sel_endianness()
  ptr_ring: fix build

vhost: validate log when IOTLB is enabled

2018-03-29T20:22:47+00:00

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

2018-03-27T17:03:18+00:00

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: fix vhost ioctl signature to build with clang

2018-03-20T01:17:42+00:00

Clang is particularly anal about signed vs unsigned comparisons and
doesn't like the fact that some ioctl numbers set the MSB, so we get
this error when trying to build vhost on aarch64:

drivers/vhost/vhost.c:1400:7: error: overflow converting case value to
 switch condition type (3221794578 to 18446744072636378898)
 [-Werror, -Wswitch]
        case VHOST_GET_VRING_BASE:

3221794578 is 0xC008AF12 in hex
18446744072636378898 is 0xFFFFFFFFC008AF12 in hex

Fix this by using unsigned ints in the function signature for
vhost_vring_ioctl().

Signed-off-by: Sonny Rao 
Reviewed-by: Darren Kenny 
Signed-off-by: Michael S. Tsirkin