4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx> commit 6712cc9c22117a8af9f3df272b4a44fd2e4201cd upstream. For unsupported device types, the vmbus channel ringbuffer is never initialized, and therefore reading the sysfs files will return garbage or cause a kernel OOPS. Fixes: c2e5df616e1a ("vmbus: add per-channel sysfs info") Signed-off-by: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 4.15 Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hv/vmbus_drv.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1178,6 +1178,9 @@ static ssize_t vmbus_chan_attr_show(stru if (!attribute->show) return -EIO; + if (chan->state != CHANNEL_OPENED_STATE) + return -EINVAL; + return attribute->show(chan, buf); }