From e44eab51e74c59a0b01c1fce2159c82b3c8a31b0 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Wed, 7 Dec 2016 01:16:28 -0800 Subject: Drivers: hv: vmbus: Prevent sending data on a rescinded channel commit e7e97dd8b77ee7366f2f8c70a033bf5fa05ec2e0 upstream. After the channel is rescinded, the host does not read from the rescinded channel. Fail writes to a channel that has already been rescinded. If we permit writes on a rescinded channel, since the host will not respond we will have situations where we will be unable to unload vmbus drivers that cannot have any outstanding requests to the host at the point they are unoaded. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/ring_buffer.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 308dbda700eb..e94ed1c22c8b 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -298,6 +298,9 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, unsigned long flags = 0; struct hv_ring_buffer_info *outring_info = &channel->outbound; + if (channel->rescind) + return -ENODEV; + for (i = 0; i < kv_count; i++) totalbytes_towrite += kv_list[i].iov_len; @@ -350,6 +353,10 @@ int hv_ringbuffer_write(struct vmbus_channel *channel, spin_unlock_irqrestore(&outring_info->ring_lock, flags); hv_signal_on_write(old_write, channel, kick_q); + + if (channel->rescind) + return -ENODEV; + return 0; } -- cgit v1.2.3