linux/net/vmw_vsock
Longpeng(Mike) 49b0b6ffe2 vsock/virtio: avoid potential deadlock when vsock device remove
There's a potential deadlock case when remove the vsock device or
process the RESET event:

  vsock_for_each_connected_socket:
      spin_lock_bh(&vsock_table_lock) ----------- (1)
      ...
          virtio_vsock_reset_sock:
              lock_sock(sk) --------------------- (2)
      ...
      spin_unlock_bh(&vsock_table_lock)

lock_sock() may do initiative schedule when the 'sk' is owned by
other thread at the same time, we would receivce a warning message
that "scheduling while atomic".

Even worse, if the next task (selected by the scheduler) try to
release a 'sk', it need to request vsock_table_lock and the deadlock
occur, cause the system into softlockup state.
  Call trace:
   queued_spin_lock_slowpath
   vsock_remove_bound
   vsock_remove_sock
   virtio_transport_release
   __vsock_release
   vsock_release
   __sock_release
   sock_close
   __fput
   ____fput

So we should not require sk_lock in this case, just like the behavior
in vhost_vsock or vmci.

Fixes: 0ea9e1d3a9 ("VSOCK: Introduce virtio_transport.ko")
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210812053056.1699-1-longpeng2@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-12 10:57:27 -07:00
..
af_vsock_tap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
af_vsock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-06-29 15:45:27 -07:00
diag.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321 2019-06-05 17:37:05 +02:00
hyperv_transport.c Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer 2021-05-14 17:37:46 +00:00
Kconfig vsock: add vsock_loopback transport 2019-12-11 15:01:23 -08:00
Makefile vsock: add vsock_loopback transport 2019-12-11 15:01:23 -08:00
virtio_transport_common.c VSOCK: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST 2021-08-03 14:30:59 -07:00
virtio_transport.c vsock/virtio: avoid potential deadlock when vsock device remove 2021-08-12 10:57:27 -07:00
vmci_transport_notify_qstate.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321 2019-06-05 17:37:05 +02:00
vmci_transport_notify.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 321 2019-06-05 17:37:05 +02:00
vmci_transport_notify.h vsock: remove include/linux/vm_sockets.h file 2019-11-14 18:12:17 -08:00
vmci_transport.c net: sock: introduce sk_error_report 2021-06-29 11:28:21 -07:00
vmci_transport.h vsock: handle buffer_size sockopts in the core 2019-11-14 18:12:18 -08:00
vsock_addr.c vsock_addr: Check for supported flag values 2020-12-14 19:33:39 -08:00
vsock_loopback.c vsock/loopback: enable SEQPACKET for transport 2021-06-11 13:32:47 -07:00