[PATCH v11 21/56] Input: atmel_mxt_ts - check data->input_dev is not null in mxt_input_sync()

Jiada Wang
2020-05-08T05:58:25Z

From: Janus Cheng <drxaero@gmail.com>

* Symptom: if update_fw and update_cfg, kernel panic occurs.
* Reproducibility: 10%
* Root Cause:
- If update_fw, the T6 will send a CFG_ERR message periodically.
- After that, update_cfg process begin, the mxt_update_cfg_store() will
invoke mxt_free_input_device() and nullify data->input_dev.
- The CFG_ERR message will trigger mxt_interrupt(), and mxt_input_sync()
will be invoked by mxt_process_messages_t44(). And mxt_input_sync()
references a NULL data->input_dev and kernel panic occurs.

TrackerRMS TKT-004235

Signed-off-by: Janus Cheng <drxaero@gmail.com>
Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
(cherry picked from ndyer/linux/for-upstream commit c909ada856861f305653b127db3ea0fa60264331)
[gdavis: Resolve forward port conflicts due to applying upstream
commit 96a938aa214e ("Input: atmel_mxt_ts - remove platform
data support").]
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Jiada Wang <jiada_wang@mentor.com>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 503e70603a67..85b903b8d5c9 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -838,9 +838,11 @@ static void mxt_input_button(struct mxt_data *data, u8 *message)

static void mxt_input_sync(struct mxt_data *data)
{
- input_mt_report_pointer_emulation(data->input_dev,
- data->t19_num_keys);
- input_sync(data->input_dev);
+ if (data->input_dev) {
+ input_mt_report_pointer_emulation(data->input_dev,
+ data->t19_num_keys);
+ input_sync(data->input_dev);
+ }
}

static void mxt_proc_t9_message(struct mxt_data *data, u8 *message)
--
2.17.1