diff mbox series

rpmsg: glink: Fix channel memory leak

Message ID 20190919100540.28159-1-srinivas.kandagatla@linaro.org
State New
Headers show
Series rpmsg: glink: Fix channel memory leak | expand

Commit Message

Srinivas Kandagatla Sept. 19, 2019, 10:05 a.m. UTC
If we stop and start the dsp while channel is open then there is a leak
in the driver as the refcount is not accounted for the open.

This patch checks if the channel is open while running cleanup code
and does an extra kref_put to account for open which would ensure
that channel does not leak.

Originally detected by kmemleak:
  backtrace:
    [<ffffff80088b74d8>] kmemleak_alloc+0x50/0x84
    [<ffffff80081ddbc8>] kmem_cache_alloc_trace+0xd4/0x178
    [<ffffff80086b8bd0>] qcom_glink_alloc_channel+0x34/0x148
    [<ffffff80086b8038>] qcom_glink_work+0x3b0/0x664
    [<ffffff80080c3da8>] process_one_work+0x160/0x2f8
    [<ffffff80080c4198>] worker_thread+0x1e8/0x2d4
    [<ffffff80080c8b24>] kthread+0x128/0x138
    [<ffffff80080845b4>] ret_from_fork+0x10/0x18
    [<ffffffffffffffff>] 0xffffffffffffffff
unreferenced object 0xffffffc02cf5ed80 (size 128):

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

---
 drivers/rpmsg/qcom_glink_native.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

-- 
2.21.0

Comments

Bjorn Andersson Sept. 20, 2019, 4:18 a.m. UTC | #1
On Thu 19 Sep 03:05 PDT 2019, Srinivas Kandagatla wrote:

> If we stop and start the dsp while channel is open then there is a leak

> in the driver as the refcount is not accounted for the open.

> 

> This patch checks if the channel is open while running cleanup code

> and does an extra kref_put to account for open which would ensure

> that channel does not leak.

> 

> Originally detected by kmemleak:

>   backtrace:

>     [<ffffff80088b74d8>] kmemleak_alloc+0x50/0x84

>     [<ffffff80081ddbc8>] kmem_cache_alloc_trace+0xd4/0x178

>     [<ffffff80086b8bd0>] qcom_glink_alloc_channel+0x34/0x148

>     [<ffffff80086b8038>] qcom_glink_work+0x3b0/0x664

>     [<ffffff80080c3da8>] process_one_work+0x160/0x2f8

>     [<ffffff80080c4198>] worker_thread+0x1e8/0x2d4

>     [<ffffff80080c8b24>] kthread+0x128/0x138

>     [<ffffff80080845b4>] ret_from_fork+0x10/0x18

>     [<ffffffffffffffff>] 0xffffffffffffffff

> unreferenced object 0xffffffc02cf5ed80 (size 128):

> 

> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

> ---

>  drivers/rpmsg/qcom_glink_native.c | 7 ++++++-

>  1 file changed, 6 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c

> index dc7d3d098fd3..38a10dcc2029 100644

> --- a/drivers/rpmsg/qcom_glink_native.c

> +++ b/drivers/rpmsg/qcom_glink_native.c

> @@ -1660,8 +1660,13 @@ void qcom_glink_native_remove(struct qcom_glink *glink)

>  

>  	spin_lock_irqsave(&glink->idr_lock, flags);

>  	/* Release any defunct local channels, waiting for close-ack */

> -	idr_for_each_entry(&glink->lcids, channel, cid)

> +	idr_for_each_entry(&glink->lcids, channel, cid) {

> +		if (channel->rcid)


Thanks for the patch Srinivas! I looked at it in your tree as I was
coming up with the fixes for the problems I hit in my testing the other
day.

But, there is a window between qcom_glink_rx_open() assigning
channel->rcid and where rpmsg_dev_probe() will invoke
qcom_glink_create_remote(), which adds the channel to lcids, i.e. where
we would leak the channel. So I instead picked Chris' patch (3/6 in my
series), which will clean up the channel in this case as well.

Regards,
Bjorn

> +			kref_put(&channel->refcount,

> +				 qcom_glink_channel_release);

> +

>  		kref_put(&channel->refcount, qcom_glink_channel_release);

> +	}

>  

>  	/* Release any defunct local channels, waiting for close-req */

>  	idr_for_each_entry(&glink->rcids, channel, cid)

> -- 

> 2.21.0

>
diff mbox series

Patch

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index dc7d3d098fd3..38a10dcc2029 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -1660,8 +1660,13 @@  void qcom_glink_native_remove(struct qcom_glink *glink)
 
 	spin_lock_irqsave(&glink->idr_lock, flags);
 	/* Release any defunct local channels, waiting for close-ack */
-	idr_for_each_entry(&glink->lcids, channel, cid)
+	idr_for_each_entry(&glink->lcids, channel, cid) {
+		if (channel->rcid)
+			kref_put(&channel->refcount,
+				 qcom_glink_channel_release);
+
 		kref_put(&channel->refcount, qcom_glink_channel_release);
+	}
 
 	/* Release any defunct local channels, waiting for close-req */
 	idr_for_each_entry(&glink->rcids, channel, cid)