HID: alps: fix use-after-free on input2 registration failure

alps_input_configured() stores data->input2 before calling
input_register_device().  If registration fails, input_free_device()
frees the input device but data->input2 still points to the freed memory.
alps_input_configured() calls hid_hw_open() before allocating input2, so
URBs are already active and raw_event can fire during the failure window.
A U1_SP_ABSOLUTE_REPORT_ID report arriving then causes u1_raw_event()
to dereference the freed data->input2 -> use-after-free.

Fix by only storing input2 into drvdata after successful registration
and adding a NULL guard in the raw_event path.

Fixes: 2562756dde55 ("HID: add Alps I2C HID Touchpad-Stick support")
Cc: stable@vger.kernel.org
Signed-off-by: Chen Changcheng <chenchangcheng@kylinos.cn>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

0 files changed, 0 insertions, 0 deletions