[PATCH 5.19 672/717] HID: nintendo: check analog user calibration for plausibility

Greg Kroah-Hartman
2022-10-22T09:16:47Z

From: Johnothan King <johnothanking@protonmail.com>

[ Upstream commit 50503e360eeb968a3d00234c9cc4057d774c3e9a ]

Arne Wendt writes:
Cheap clone controllers may (falsely) report as having a user
calibration for the analog sticks in place, but return
wrong/impossible values for the actual calibration data.
In the present case at mine, the controller reports having a
user calibration in place and successfully executes the read
commands. The reported user calibration however is
min = center = max = 0.

This pull request addresses problems of this kind by checking the
provided user calibration-data for plausibility (min < center < max)
and falling back to the default values if implausible.

I'll note that I was experiencing a crash because of this bug when using
the GuliKit KingKong 2 controller. The crash manifests as a divide by
zero error in the kernel logs:
kernel: divide error: 0000 [#1] PREEMPT SMP NOPTI

Link: https://github.com/nicman23/dkms-hid-nintendo/pull/25
Link: https://github.com/DanielOgorchock/linux/issues/36
Co-authored-by: Arne Wendt <arne.wendt@tuhh.de>
Signed-off-by: Johnothan King <johnothanking@protonmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/gvpL2G6VwXGJPvxX5KRiu9pVjvTivgayug_jdKDY6zfuAaAqncP9BkKLosjwUXNlgVVTMfJSKfwPF1K79cKAkwGComyC21vCV3q9B3EXNkE=@protonmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hid/hid-nintendo.c | 55 +++++++++++++++++++++-----------------
1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/drivers/hid/hid-nintendo.c b/drivers/hid/hid-nintendo.c
index f33a03c96ba6..cce324887952 100644
--- a/drivers/hid/hid-nintendo.c
+++ b/drivers/hid/hid-nintendo.c
@@ -761,12 +761,31 @@ static int joycon_read_stick_calibration(struct joycon_ctlr *ctlr, u16 cal_addr,
cal_y->max = cal_y->center + y_max_above;
cal_y->min = cal_y->center - y_min_below;

- return 0;
+ /* check if calibration values are plausible */
+ if (cal_x->min >= cal_x->center || cal_x->center >= cal_x->max ||
+ cal_y->min >= cal_y->center || cal_y->center >= cal_y->max)
+ ret = -EINVAL;
+
+ return ret;
}

static const u16 DFLT_STICK_CAL_CEN = 2000;
static const u16 DFLT_STICK_CAL_MAX = 3500;
static const u16 DFLT_STICK_CAL_MIN = 500;
+static void joycon_use_default_calibration(struct hid_device *hdev,
+ struct joycon_stick_cal *cal_x,
+ struct joycon_stick_cal *cal_y,
+ const char *stick, int ret)
+{
+ hid_warn(hdev,
+ "Failed to read %s stick cal, using defaults; e=%d\n",
+ stick, ret);
+
+ cal_x->center = cal_y->center = DFLT_STICK_CAL_CEN;
+ cal_x->max = cal_y->max = DFLT_STICK_CAL_MAX;
+ cal_x->min = cal_y->min = DFLT_STICK_CAL_MIN;
+}
+
static int joycon_request_calibration(struct joycon_ctlr *ctlr)
{
u16 left_stick_addr = JC_CAL_FCT_DATA_LEFT_ADDR;
@@ -794,38 +813,24 @@ static int joycon_request_calibration(struct joycon_ctlr *ctlr)
&ctlr->left_stick_cal_x,
&ctlr->left_stick_cal_y,
true);
- if (ret) {
- hid_warn(ctlr->hdev,
- "Failed to read left stick cal, using dflts; e=%d\n",
- ret);
-
- ctlr->left_stick_cal_x.center = DFLT_STICK_CAL_CEN;
- ctlr->left_stick_cal_x.max = DFLT_STICK_CAL_MAX;
- ctlr->left_stick_cal_x.min = DFLT_STICK_CAL_MIN;

- ctlr->left_stick_cal_y.center = DFLT_STICK_CAL_CEN;
- ctlr->left_stick_cal_y.max = DFLT_STICK_CAL_MAX;
- ctlr->left_stick_cal_y.min = DFLT_STICK_CAL_MIN;
- }
+ if (ret)
+ joycon_use_default_calibration(ctlr->hdev,
+ &ctlr->left_stick_cal_x,
+ &ctlr->left_stick_cal_y,
+ "left", ret);

/* read the right stick calibration data */
ret = joycon_read_stick_calibration(ctlr, right_stick_addr,
&ctlr->right_stick_cal_x,
&ctlr->right_stick_cal_y,
false);
- if (ret) {
- hid_warn(ctlr->hdev,
- "Failed to read right stick cal, using dflts; e=%d\n",
- ret);
-
- ctlr->right_stick_cal_x.center = DFLT_STICK_CAL_CEN;
- ctlr->right_stick_cal_x.max = DFLT_STICK_CAL_MAX;
- ctlr->right_stick_cal_x.min = DFLT_STICK_CAL_MIN;

- ctlr->right_stick_cal_y.center = DFLT_STICK_CAL_CEN;
- ctlr->right_stick_cal_y.max = DFLT_STICK_CAL_MAX;
- ctlr->right_stick_cal_y.min = DFLT_STICK_CAL_MIN;
- }
+ if (ret)
+ joycon_use_default_calibration(ctlr->hdev,
+ &ctlr->right_stick_cal_x,
+ &ctlr->right_stick_cal_y,
+ "right", ret);

hid_dbg(ctlr->hdev, "calibration:\n"
"l_x_c=%d l_x_max=%d l_x_min=%d\n"
--
2.35.1