[PATCH 5.4 216/261] gnss: sirf: fix error return code in sirf_probe()

From: Greg Kroah-Hartman
Date: Fri Jun 19 2020 - 12:00:21 EST


From: Wei Yongjun <weiyongjun1@xxxxxxxxxx>

commit 43d7ce70ae43dd8523754b17f567417e0e75dbce upstream.

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

This avoids a use-after-free in case the driver is later unbound.

Fixes: d2efbbd18b1e ("gnss: add driver for sirfstar-based receivers")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
[ johan: amend commit message; mention potential use-after-free ]
Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.19
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gnss/sirf.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -439,14 +439,18 @@ static int sirf_probe(struct serdev_devi

data->on_off = devm_gpiod_get_optional(dev, "sirf,onoff",
GPIOD_OUT_LOW);
- if (IS_ERR(data->on_off))
+ if (IS_ERR(data->on_off)) {
+ ret = PTR_ERR(data->on_off);
goto err_put_device;
+ }

if (data->on_off) {
data->wakeup = devm_gpiod_get_optional(dev, "sirf,wakeup",
GPIOD_IN);
- if (IS_ERR(data->wakeup))
+ if (IS_ERR(data->wakeup)) {
+ ret = PTR_ERR(data->wakeup);
goto err_put_device;
+ }

ret = regulator_enable(data->vcc);
if (ret)