[PATCH 4.9 16/22] Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels

Greg Kroah-Hartman
2018-12-28T12:17:35Z

From: Dexuan Cui <decui@microsoft.com>

commit fc96df16a1ce80cbb3c316ab7d4dc8cd5c2852ce upstream.

Before 98f4c651762c, we returned zeros for unopened channels.
With 98f4c651762c, we started to return random on-stack values.

We'd better return -EINVAL instead.

Fixes: 98f4c651762c ("hv: move ringbuffer bus attributes to dev_groups")
Cc: stable@vger.kernel.org
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hv/vmbus_drv.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -317,6 +317,8 @@ static ssize_t out_intr_mask_show(struct

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
}
@@ -330,6 +332,8 @@ static ssize_t out_read_index_show(struc

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
return sprintf(buf, "%d\n", outbound.current_read_index);
}
@@ -344,6 +348,8 @@ static ssize_t out_write_index_show(stru

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
return sprintf(buf, "%d\n", outbound.current_write_index);
}
@@ -358,6 +364,8 @@ static ssize_t out_read_bytes_avail_show

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
}
@@ -372,6 +380,8 @@ static ssize_t out_write_bytes_avail_sho

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
}
@@ -385,6 +395,8 @@ static ssize_t in_intr_mask_show(struct

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
}
@@ -398,6 +410,8 @@ static ssize_t in_read_index_show(struct

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
return sprintf(buf, "%d\n", inbound.current_read_index);
}
@@ -411,6 +425,8 @@ static ssize_t in_write_index_show(struc

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
return sprintf(buf, "%d\n", inbound.current_write_index);
}
@@ -425,6 +441,8 @@ static ssize_t in_read_bytes_avail_show(

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
}
@@ -439,6 +457,8 @@ static ssize_t in_write_bytes_avail_show

if (!hv_dev->channel)
return -ENODEV;
+ if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
+ return -EINVAL;
hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
}