linux-stable.git/drivers/vhost, branch linux-6.10.y

vhost/scsi: null-ptr-dereference in vhost_scsi_get_req()

2024-10-10T10:01:13+00:00

commit 221af82f606d928ccef19a16d35633c63026f1be upstream.

Since commit 3f8ca2e115e5 ("vhost/scsi: Extract common handling code
from control queue handler") a null pointer dereference bug can be
triggered when guest sends an SCSI AN request.

In vhost_scsi_ctl_handle_vq(), `vc.target` is assigned with
`&v_req.tmf.lun[1]` within a switch-case block and is then passed to
vhost_scsi_get_req() which extracts `vc->req` and `tpg`. However, for
a `VIRTIO_SCSI_T_AN_*` request, tpg is not required, so `vc.target` is
set to NULL in this branch. Later, in vhost_scsi_get_req(),
`vc->target` is dereferenced without being checked, leading to a null
pointer dereference bug. This bug can be triggered from guest.

When this bug occurs, the vhost_worker process is killed while holding
`vq->mutex` and the corresponding tpg will remain occupied
indefinitely.

Below is the KASAN report:
Oops: general protection fault, probably for non-canonical address
0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 PID: 840 Comm: poc Not tainted 6.10.0+ #1
Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS
1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:vhost_scsi_get_req+0x165/0x3a0
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 02 00 00
48 b8 00 00 00 00 00 fc ff df 4d 8b 65 30 4c 89 e2 48 c1 ea 03 <0f> b6
04 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 be 01 00 00
RSP: 0018:ffff888017affb50 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88801b000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888017affcb8
RBP: ffff888017affb80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff888017affc88 R14: ffff888017affd1c R15: ffff888017993000
FS:  000055556e076500(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200027c0 CR3: 0000000010ed0004 CR4: 0000000000370ef0
Call Trace:
 
 ? show_regs+0x86/0xa0
 ? die_addr+0x4b/0xd0
 ? exc_general_protection+0x163/0x260
 ? asm_exc_general_protection+0x27/0x30
 ? vhost_scsi_get_req+0x165/0x3a0
 vhost_scsi_ctl_handle_vq+0x2a4/0xca0
 ? __pfx_vhost_scsi_ctl_handle_vq+0x10/0x10
 ? __switch_to+0x721/0xeb0
 ? __schedule+0xda5/0x5710
 ? __kasan_check_write+0x14/0x30
 ? _raw_spin_lock+0x82/0xf0
 vhost_scsi_ctl_handle_kick+0x52/0x90
 vhost_run_work_list+0x134/0x1b0
 vhost_task_fn+0x121/0x350
...
 
---[ end trace 0000000000000000 ]---

Let's add a check in vhost_scsi_get_req.

Fixes: 3f8ca2e115e5 ("vhost/scsi: Extract common handling code from control queue handler")
Signed-off-by: Haoran Zhang 
[whitespace fixes]
Signed-off-by: Mike Christie 
Message-Id: 
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Greg Kroah-Hartman

vhost_vdpa: assign irq bypass producer token correctly

2024-10-04T14:33:19+00:00

[ Upstream commit 02e9e9366fefe461719da5d173385b6685f70319 ]

We used to call irq_bypass_unregister_producer() in
vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the
token pointer is still valid or not.

Actually, we use the eventfd_ctx as the token so the life cycle of the
token should be bound to the VHOST_SET_VRING_CALL instead of
vhost_vdpa_setup_vq_irq() which could be called by set_status().

Fixing this by setting up irq bypass producer's token when handling
VHOST_SET_VRING_CALL and un-registering the producer before calling
vhost_vring_ioctl() to prevent a possible use after free as eventfd
could have been released in vhost_vring_ioctl(). And such registering
and unregistering will only be done if DRIVER_OK is set.

Reported-by: Dragos Tatulea 
Tested-by: Dragos Tatulea 
Reviewed-by: Dragos Tatulea 
Fixes: 2cf1ba9a4d15 ("vhost_vdpa: implement IRQ offloading in vhost_vdpa")
Signed-off-by: Jason Wang 
Message-Id: <20240816031900.18013-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Signed-off-by: Sasha Levin

vhost-vdpa: switch to use vmf_insert_pfn() in the fault handler

2024-08-14T13:34:29+00:00

commit 0823dc64586ba5ea13a7d200a5d33e4c5fa45950 upstream.

remap_pfn_page() should not be called in the fault handler as it may
change the vma->flags which may trigger lockdep warning since the vma
write lock is not held. Actually there's no need to modify the
vma->flags as it has been set in the mmap(). So this patch switches to
use vmf_insert_pfn() instead.

Reported-by: Dragos Tatulea 
Tested-by: Dragos Tatulea 
Fixes: ddd89d0a059d ("vhost_vdpa: support doorbell mapping via mmap")
Cc: stable@vger.kernel.org
Signed-off-by: Jason Wang 
Message-Id: <20240701033159.18133-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Michal Kubiak 
Signed-off-by: Greg Kroah-Hartman

vhost/vsock: always initialize seqpacket_allow

2024-08-03T07:00:15+00:00

[ Upstream commit 1e1fdcbdde3b7663e5d8faeb2245b9b151417d22 ]

There are two issues around seqpacket_allow:
1. seqpacket_allow is not initialized when socket is
   created. Thus if features are never set, it will be
   read uninitialized.
2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared,
   then seqpacket_allow will not be cleared appropriately
   (existing apps I know about don't usually do this but
    it's legal and there's no way to be sure no one relies
    on this).

To fix:
	- initialize seqpacket_allow after allocation
	- set it unconditionally in set_features

Reported-by: syzbot+6c21aeb59d0e82eb2782@syzkaller.appspotmail.com
Reported-by: Jeongjun Park 
Fixes: ced7b713711f ("vhost/vsock: support SEQPACKET for transport").
Tested-by: Arseny Krasnov 
Cc: David S. Miller 
Cc: Stefan Hajnoczi 
Message-ID: <20240422100010-mutt-send-email-mst@kernel.org>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang 
Reviewed-by: Stefano Garzarella 
Reviewed-by: Eugenio Pérez 
Acked-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

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

2024-05-23T19:04:36+00:00

Pull virtio updates from Michael Tsirkin:
 "Several new features here:

   - virtio-net is finally supported in vduse

   - virtio (balloon and mem) interaction with suspend is improved

   - vhost-scsi now handles signals better/faster

  And fixes, cleanups all over the place"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits)
  virtio-pci: Check if is_avq is NULL
  virtio: delete vq in vp_find_vqs_msix() when request_irq() fails
  MAINTAINERS: add Eugenio Pérez as reviewer
  vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API
  vp_vdpa: don't allocate unused msix vectors
  sound: virtio: drop owner assignment
  fuse: virtio: drop owner assignment
  scsi: virtio: drop owner assignment
  rpmsg: virtio: drop owner assignment
  nvdimm: virtio_pmem: drop owner assignment
  wifi: mac80211_hwsim: drop owner assignment
  vsock/virtio: drop owner assignment
  net: 9p: virtio: drop owner assignment
  net: virtio: drop owner assignment
  net: caif: virtio: drop owner assignment
  misc: nsm: drop owner assignment
  iommu: virtio: drop owner assignment
  drm/virtio: drop owner assignment
  gpio: virtio: drop owner assignment
  firmware: arm_scmi: virtio: drop owner assignment
  ...

vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API

2024-05-22T12:31:18+00:00

ida_alloc() and ida_free() should be preferred to the deprecated
ida_simple_get() and ida_simple_remove().

Note that the upper limit of ida_simple_get() is exclusive, but the one of
ida_alloc_max() is inclusive. So a -1 has been added when needed.

Signed-off-by: Christophe JAILLET 
Reviewed-by: Simon Horman 
Message-Id: <67c2edf49788c27d5f7a49fc701520b9fcf739b5.1713088999.git.christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang

vhost_task: Handle SIGKILL by flushing work and exiting

2024-05-22T12:31:15+00:00

Instead of lingering until the device is closed, this has us handle
SIGKILL by:

1. marking the worker as killed so we no longer try to use it with
   new virtqueues and new flush operations.
2. setting the virtqueue to worker mapping so no new works are queued.
3. running all the exiting works.

Suggested-by: Edward Adam Davis 
Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com
Message-Id: 
Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-9-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost: Release worker mutex during flushes

2024-05-22T12:31:15+00:00

In the next patches where the worker can be killed while in use, we
need to be able to take the worker mutex and kill queued works for
new IO and flushes, and set some new flags to prevent new
__vhost_vq_attach_worker calls from swapping in/out killed workers.

If we are holding the worker mutex during a flush and the flush's work
is still in the queue, the worker code that will handle the SIGKILL
cleanup won't be able to take the mutex and perform it's cleanup. So
this patch has us drop the worker mutex while waiting for the flush
to complete.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-8-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost: Use virtqueue mutex for swapping worker

2024-05-22T12:31:15+00:00

__vhost_vq_attach_worker uses the vhost_dev mutex to serialize the
swapping of a virtqueue's worker. This was done for simplicity because
we are already holding that mutex.

In the next patches where the worker can be killed while in use, we need
finer grained locking because some drivers will hold the vhost_dev mutex
while flushing. However in the SIGKILL handler in the next patches, we
will need to be able to swap workers (set current one to NULL), kill
queued works and stop new flushes while flushes are in progress.

To prepare us, this has us use the virtqueue mutex for swapping workers
instead of the vhost_dev one.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-7-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin

vhost_scsi: Handle vhost_vq_work_queue failures for TMFs

2024-05-22T12:31:15+00:00

vhost_vq_work_queue will never fail when queueing the TMF's response
handling because a guest can only send us TMFs when the device is fully
setup so there is always a worker at that time. In the next patches we
will modify the worker code so it handles SIGKILL by exiting before
outstanding commands/TMFs have sent their responses. In that case
vhost_vq_work_queue can fail when we try to send a response.

This has us just free the TMF's resources since at this time the guest
won't be able to get a response even if we could send it.

Signed-off-by: Mike Christie 
Message-Id: <20240316004707.45557-6-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin