linux-stable.git/net/vmw_vsock, branch v5.11 Linux kernel stable tree vsock: fix locking in vsock_shutdown() 2021-02-09T23:31:22+00:00 Stefano Garzarella sgarzare@redhat.com 2021-02-09T08:52:19+00:00 1c5fae9c9a092574398a17facc31c533791ef232 In vsock_shutdown() we touched some socket fields without holding the socket lock, such as 'state' and 'sk_flags'. Also, after the introduction of multi-transport, we are accessing 'vsk->transport' in vsock_send_shutdown() without holding the lock and this call can be made while the connection is in progress, so the transport can change in the meantime. To avoid issues, we hold the socket lock when we enter in vsock_shutdown() and release it when we leave. Among the transports that implement the 'shutdown' callback, only hyperv_transport acquired the lock. Since the caller now holds it, we no longer take it. Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In vsock_shutdown() we touched some socket fields without holding the
socket lock, such as 'state' and 'sk_flags'.

Also, after the introduction of multi-transport, we are accessing
'vsk->transport' in vsock_send_shutdown() without holding the lock
and this call can be made while the connection is in progress, so
the transport can change in the meantime.

To avoid issues, we hold the socket lock when we enter in
vsock_shutdown() and release it when we leave.

Among the transports that implement the 'shutdown' callback, only
hyperv_transport acquired the lock. Since the caller now holds it,
we no longer take it.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
vsock/virtio: update credit only if socket is not closed 2021-02-08T21:27:46+00:00 Stefano Garzarella sgarzare@redhat.com 2021-02-08T14:44:54+00:00 ce7536bc7398e2ae552d2fabb7e0e371a9f1fe46 If the socket is closed or is being released, some resources used by virtio_transport_space_update() such as 'vsk->trans' may be released. To avoid a use after free bug we should only update the available credit when we are sure the socket is still open and we have the lock held. Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko") Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20210208144454.84438-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
If the socket is closed or is being released, some resources used by
virtio_transport_space_update() such as 'vsk->trans' may be released.

To avoid a use after free bug we should only update the available credit
when we are sure the socket is still open and we have the lock held.

Fixes: 06a8fc78367d ("VSOCK: Introduce virtio_vsock_common.ko")
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20210208144454.84438-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/vmw_vsock: improve locking in vsock_connect_timeout() 2021-02-06T23:03:31+00:00 Norbert Slusarek nslusarek@gmx.net 2021-02-05T12:14:05+00:00 3d0bc44d39bca615b72637e340317b7899b7f911 A possible locking issue in vsock_connect_timeout() was recognized by Eric Dumazet which might cause a null pointer dereference in vsock_transport_cancel_pkt(). This patch assures that vsock_transport_cancel_pkt() will be called within the lock, so a race condition won't occur which could result in vsk->transport to be set to NULL. Fixes: 380feae0def7 ("vsock: cancel packets when failing to connect") Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Norbert Slusarek <nslusarek@gmx.net> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/trinity-f8e0937a-cf0e-4d80-a76e-d9a958ba3ef1-1612535522360@3c-app-gmx-bap12 Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
A possible locking issue in vsock_connect_timeout() was recognized by
Eric Dumazet which might cause a null pointer dereference in
vsock_transport_cancel_pkt(). This patch assures that
vsock_transport_cancel_pkt() will be called within the lock, so a race
condition won't occur which could result in vsk->transport to be set to NULL.

Fixes: 380feae0def7 ("vsock: cancel packets when failing to connect")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Norbert Slusarek <nslusarek@gmx.net>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/trinity-f8e0937a-cf0e-4d80-a76e-d9a958ba3ef1-1612535522360@3c-app-gmx-bap12
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/vmw_vsock: fix NULL pointer dereference 2021-02-06T23:03:17+00:00 Norbert Slusarek nslusarek@gmx.net 2021-02-05T12:12:06+00:00 5d1cbcc990f18edaddddef26677073c4e6fad7b7 In vsock_stream_connect(), a thread will enter schedule_timeout(). While being scheduled out, another thread can enter vsock_stream_connect() as well and set vsk->transport to NULL. In case a signal was sent, the first thread can leave schedule_timeout() and vsock_transport_cancel_pkt() will be called right after. Inside vsock_transport_cancel_pkt(), a null dereference will happen on transport->cancel_pkt. Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") Signed-off-by: Norbert Slusarek <nslusarek@gmx.net> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/r/trinity-c2d6cede-bfb1-44e2-85af-1fbc7f541715-1612535117028@3c-app-gmx-bap12 Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
In vsock_stream_connect(), a thread will enter schedule_timeout().
While being scheduled out, another thread can enter vsock_stream_connect()
as well and set vsk->transport to NULL. In case a signal was sent, the
first thread can leave schedule_timeout() and vsock_transport_cancel_pkt()
will be called right after. Inside vsock_transport_cancel_pkt(), a null
dereference will happen on transport->cancel_pkt.

Fixes: c0cfa2d8a788 ("vsock: add multi-transports support")
Signed-off-by: Norbert Slusarek <nslusarek@gmx.net>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/trinity-c2d6cede-bfb1-44e2-85af-1fbc7f541715-1612535117028@3c-app-gmx-bap12
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vsock: fix the race conditions in multi-transport support 2021-02-02T03:54:30+00:00 Alexander Popov alex.popov@linux.com 2021-02-01T08:47:19+00:00 c518adafa39f37858697ac9309c6cf1805581446 There are multiple similar bugs implicitly introduced by the commit c0cfa2d8a788fcf4 ("vsock: add multi-transports support") and commit 6a2c0962105ae8ce ("vsock: prevent transport modules unloading"). The bug pattern: [1] vsock_sock.transport pointer is copied to a local variable, [2] lock_sock() is called, [3] the local variable is used. VSOCK multi-transport support introduced the race condition: vsock_sock.transport value may change between [1] and [2]. Let's copy vsock_sock.transport pointer to local variables after the lock_sock() call. Fixes: c0cfa2d8a788fcf4 ("vsock: add multi-transports support") Signed-off-by: Alexander Popov <alex.popov@linux.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Jorgen Hansen <jhansen@vmware.com> Link: https://lore.kernel.org/r/20210201084719.2257066-1-alex.popov@linux.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
There are multiple similar bugs implicitly introduced by the
commit c0cfa2d8a788fcf4 ("vsock: add multi-transports support") and
commit 6a2c0962105ae8ce ("vsock: prevent transport modules unloading").

The bug pattern:
 [1] vsock_sock.transport pointer is copied to a local variable,
 [2] lock_sock() is called,
 [3] the local variable is used.
VSOCK multi-transport support introduced the race condition:
vsock_sock.transport value may change between [1] and [2].

Let's copy vsock_sock.transport pointer to local variables after
the lock_sock() call.

Fixes: c0cfa2d8a788fcf4 ("vsock: add multi-transports support")
Signed-off-by: Alexander Popov <alex.popov@linux.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Link: https://lore.kernel.org/r/20210201084719.2257066-1-alex.popov@linux.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
af_vsock: Assign the vsock transport considering the vsock address flags 2020-12-15T03:33:39+00:00 Andra Paraschiv andraprs@amazon.com 2020-12-14T16:11:22+00:00 7f816984f439dfe24da25032254cb10512900346 The vsock flags field can be set in the connect path (user space app) and the (listen) receive path (kernel space logic). When the vsock transport is assigned, the remote CID is used to distinguish between types of connection. Use the vsock flags value (in addition to the CID) from the remote address to decide which vsock transport to assign. For the sibling VMs use case, all the vsock packets need to be forwarded to the host, so always assign the guest->host transport if the VMADDR_FLAG_TO_HOST flag is set. For the other use cases, the vsock transport assignment logic is not changed. Changelog v3 -> v4 * Update the "remote_flags" local variable type to reflect the change of the "svm_flags" field to be 1 byte in size. v2 -> v3 * Update bitwise check logic to not compare result to the flag value. v1 -> v2 * Use bitwise operator to check the vsock flag. * Use the updated "VMADDR_FLAG_TO_HOST" flag naming. * Merge the checks for the g2h transport assignment in one "if" block. Signed-off-by: Andra Paraschiv <andraprs@amazon.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
The vsock flags field can be set in the connect path (user space app)
and the (listen) receive path (kernel space logic).

When the vsock transport is assigned, the remote CID is used to
distinguish between types of connection.

Use the vsock flags value (in addition to the CID) from the remote
address to decide which vsock transport to assign. For the sibling VMs
use case, all the vsock packets need to be forwarded to the host, so
always assign the guest->host transport if the VMADDR_FLAG_TO_HOST flag
is set. For the other use cases, the vsock transport assignment logic is
not changed.

Changelog

v3 -> v4

* Update the "remote_flags" local variable type to reflect the change of
  the "svm_flags" field to be 1 byte in size.

v2 -> v3

* Update bitwise check logic to not compare result to the flag value.

v1 -> v2

* Use bitwise operator to check the vsock flag.
* Use the updated "VMADDR_FLAG_TO_HOST" flag naming.
* Merge the checks for the g2h transport assignment in one "if" block.

Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path 2020-12-15T03:33:39+00:00 Andra Paraschiv andraprs@amazon.com 2020-12-14T16:11:21+00:00 1b5f2ab98e7f99f1a83960b17c5596012a7c5e88 The vsock flags can be set during the connect() setup logic, when initializing the vsock address data structure variable. Then the vsock transport is assigned, also considering this flags field. The vsock transport is also assigned on the (listen) receive path. The flags field needs to be set considering the use case. Set the value of the vsock flags of the remote address to the one targeted for packets forwarding to the host, if the following conditions are met: * The source CID of the packet is higher than VMADDR_CID_HOST. * The destination CID of the packet is higher than VMADDR_CID_HOST. Changelog v3 -> v4 * No changes. v2 -> v3 * No changes. v1 -> v2 * Set the vsock flag on the receive path in the vsock transport assignment logic. * Use bitwise operator for the vsock flag setup. * Use the updated "VMADDR_FLAG_TO_HOST" flag naming. Signed-off-by: Andra Paraschiv <andraprs@amazon.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
The vsock flags can be set during the connect() setup logic, when
initializing the vsock address data structure variable. Then the vsock
transport is assigned, also considering this flags field.

The vsock transport is also assigned on the (listen) receive path. The
flags field needs to be set considering the use case.

Set the value of the vsock flags of the remote address to the one
targeted for packets forwarding to the host, if the following conditions
are met:

* The source CID of the packet is higher than VMADDR_CID_HOST.
* The destination CID of the packet is higher than VMADDR_CID_HOST.

Changelog

v3 -> v4

* No changes.

v2 -> v3

* No changes.

v1 -> v2

* Set the vsock flag on the receive path in the vsock transport
  assignment logic.
* Use bitwise operator for the vsock flag setup.
* Use the updated "VMADDR_FLAG_TO_HOST" flag naming.

Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vsock_addr: Check for supported flag values 2020-12-15T03:33:39+00:00 Andra Paraschiv andraprs@amazon.com 2020-12-14T16:11:20+00:00 cada7ccd9dc75fc73de9342ae1dd0374e8fb1056 Check if the provided flags value from the vsock address data structure includes the supported flags in the corresponding kernel version. The first byte of the "svm_zero" field is used as "svm_flags", so add the flags check instead. Changelog v3 -> v4 * New patch in v4. Signed-off-by: Andra Paraschiv <andraprs@amazon.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Check if the provided flags value from the vsock address data structure
includes the supported flags in the corresponding kernel version.

The first byte of the "svm_zero" field is used as "svm_flags", so add
the flags check instead.

Changelog

v3 -> v4

* New patch in v4.

Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-11-28T02:25:27+00:00 Jakub Kicinski kuba@kernel.org 2020-11-28T02:25:27+00:00 5c39f26e67c984db0fa95f9faecf06eb0198dce7 Trivial conflict in CAN, keep the net-next + the byteswap wrapper. Conflicts: drivers/net/can/usb/gs_usb.c Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Trivial conflict in CAN, keep the net-next + the byteswap wrapper.

Conflicts:
	drivers/net/can/usb/gs_usb.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vsock/virtio: discard packets only when socket is really closed 2020-11-24T00:36:29+00:00 Stefano Garzarella sgarzare@redhat.com 2020-11-20T10:47:36+00:00 3fe356d58efae54dade9ec94ea7c919ed20cf4db Starting from commit 8692cefc433f ("virtio_vsock: Fix race condition in virtio_transport_recv_pkt"), we discard packets in virtio_transport_recv_pkt() if the socket has been released. When the socket is connected, we schedule a delayed work to wait the RST packet from the other peer, also if SHUTDOWN_MASK is set in sk->sk_shutdown. This is done to complete the virtio-vsock shutdown algorithm, releasing the port assigned to the socket definitively only when the other peer has consumed all the packets. If we discard the RST packet received, the socket will be closed only when the VSOCK_CLOSE_TIMEOUT is reached. Sergio discovered the issue while running ab(1) HTTP benchmark using libkrun [1] and observing a latency increase with that commit. To avoid this issue, we discard packet only if the socket is really closed (SOCK_DONE flag is set). We also set SOCK_DONE in virtio_transport_release() when we don't need to wait any packets from the other peer (we didn't schedule the delayed work). In this case we remove the socket from the vsock lists, releasing the port assigned. [1] https://github.com/containers/libkrun Fixes: 8692cefc433f ("virtio_vsock: Fix race condition in virtio_transport_recv_pkt") Cc: justin.he@arm.com Reported-by: Sergio Lopez <slp@redhat.com> Tested-by: Sergio Lopez <slp@redhat.com> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Jia He <justin.he@arm.com> Link: https://lore.kernel.org/r/20201120104736.73749-1-sgarzare@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Starting from commit 8692cefc433f ("virtio_vsock: Fix race condition
in virtio_transport_recv_pkt"), we discard packets in
virtio_transport_recv_pkt() if the socket has been released.

When the socket is connected, we schedule a delayed work to wait the
RST packet from the other peer, also if SHUTDOWN_MASK is set in
sk->sk_shutdown.
This is done to complete the virtio-vsock shutdown algorithm, releasing
the port assigned to the socket definitively only when the other peer
has consumed all the packets.

If we discard the RST packet received, the socket will be closed only
when the VSOCK_CLOSE_TIMEOUT is reached.

Sergio discovered the issue while running ab(1) HTTP benchmark using
libkrun [1] and observing a latency increase with that commit.

To avoid this issue, we discard packet only if the socket is really
closed (SOCK_DONE flag is set).
We also set SOCK_DONE in virtio_transport_release() when we don't need
to wait any packets from the other peer (we didn't schedule the delayed
work). In this case we remove the socket from the vsock lists, releasing
the port assigned.

[1] https://github.com/containers/libkrun

Fixes: 8692cefc433f ("virtio_vsock: Fix race condition in virtio_transport_recv_pkt")
Cc: justin.he@arm.com
Reported-by: Sergio Lopez <slp@redhat.com>
Tested-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jia He <justin.he@arm.com>
Link: https://lore.kernel.org/r/20201120104736.73749-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>