The channel level "_show" functions are vulnerable to race conditions. Add a mutex lock and unlock around the call to the channel level "_show" functions in vmbus_chan_attr_show(). This problem was discussed here: https://lkml.org/lkml/2018/10/18/830 Signed-off-by: Kimberly Brown <kimbrownkd@xxxxxxxxx> --- drivers/hv/vmbus_drv.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 403fee01572c..e8189bc168da 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1414,6 +1414,7 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj, = container_of(attr, struct vmbus_chan_attribute, attr); const struct vmbus_channel *chan = container_of(kobj, struct vmbus_channel, kobj); + ssize_t ret; if (!attribute->show) return -EIO; @@ -1421,7 +1422,10 @@ static ssize_t vmbus_chan_attr_show(struct kobject *kobj, if (chan->state != CHANNEL_OPENED_STATE) return -EINVAL; - return attribute->show(chan, buf); + mutex_lock(&vmbus_connection.channel_mutex); + ret = attribute->show(chan, buf); + mutex_unlock(&vmbus_connection.channel_mutex); + return ret; } static const struct sysfs_ops vmbus_chan_sysfs_ops = { -- 2.17.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
