| From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 094/104] net/vmw_vsock: fix NULL pointer dereference | Date | Mon, 15 Feb 2021 16:27:47 +0100 |
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From: Norbert Slusarek <nslusarek@gmx.net>
commit 5d1cbcc990f18edaddddef26677073c4e6fad7b7 upstream.
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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/vmw_vsock/af_vsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1216,7 +1216,7 @@ static int vsock_transport_cancel_pkt(st { const struct vsock_transport *transport = vsk->transport; - if (!transport->cancel_pkt) + if (!transport || !transport->cancel_pkt) return -EOPNOTSUPP; return transport->cancel_pkt(vsk);
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