From: K. Y. Srinivasan Date: Wed, 7 Dec 2016 09:16:28 +0000 (-0800) Subject: Drivers: hv: vmbus: Prevent sending data on a rescinded channel X-Git-Tag: C0P2-H0.0--20200415~9996 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=e44eab51e74c59a0b01c1fce2159c82b3c8a31b0;p=linux.git Drivers: hv: vmbus: Prevent sending data on a rescinded channel commit e7e97dd8b77ee7366f2f8c70a033bf5fa05ec2e0 upstream. After the channel is rescinded, the host does not read from the rescinded channel. Fail writes to a channel that has already been rescinded. If we permit writes on a rescinded channel, since the host will not respond we will have situations where we will be unable to unload vmbus drivers that cannot have any outstanding requests to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 --- 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; }