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author | Hans de Goede <hdegoede@redhat.com> | 2023-04-15 18:07:31 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-30 14:03:18 +0100 |
commit | 72c28207c19c2c46fab8ae994aff25e197fb2949 (patch) | |
tree | a53c709c62f6dcd25ffcc6a90188607cbd6cb016 | |
parent | 0456b912121e45b3ef54abe3135e5dcb541f956c (diff) | |
download | linux-72c28207c19c2c46fab8ae994aff25e197fb2949.tar.gz |
power: supply: bq25890: Fix external_power_changed race
commit 029a443b9b6424170f00f6dd5b7682e682cce92e upstream. bq25890_charger_external_power_changed() dereferences bq->charger, which gets sets in bq25890_power_supply_init() like this: bq->charger = devm_power_supply_register(bq->dev, &bq->desc, &psy_cfg); As soon as devm_power_supply_register() has called device_add() the external_power_changed callback can get called. So there is a window where bq25890_charger_external_power_changed() may get called while bq->charger has not been set yet leading to a NULL pointer dereference. This race hits during boot sometimes on a Lenovo Yoga Book 1 yb1-x90f when the cht_wcove_pwrsrc (extcon) power_supply is done with detecting the connected charger-type which happens to exactly hit the small window: BUG: kernel NULL pointer dereference, address: 0000000000000018 <snip> RIP: 0010:__power_supply_is_supplied_by+0xb/0xb0 <snip> Call Trace: <TASK> __power_supply_get_supplier_property+0x19/0x50 class_for_each_device+0xb1/0xe0 power_supply_get_property_from_supplier+0x2e/0x50 bq25890_charger_external_power_changed+0x38/0x1b0 [bq25890_charger] __power_supply_changed_work+0x30/0x40 class_for_each_device+0xb1/0xe0 power_supply_changed_work+0x5f/0xe0 <snip> Fixing this is easy. The external_power_changed callback gets passed the power_supply which will eventually get stored in bq->charger, so bq25890_charger_external_power_changed() can simply directly use the passed in psy argument which is always valid. Fixes: eab25b4f93aa ("power: supply: bq25890: On the bq25892 set the IINLIM based on external charger detection") Cc: stable@vger.kernel.org Cc: Marek Vasut <marex@denx.de> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | drivers/power/supply/bq25890_charger.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/power/supply/bq25890_charger.c b/drivers/power/supply/bq25890_charger.c index 0e15302b8df2..f9ee843c8082 100644 --- a/drivers/power/supply/bq25890_charger.c +++ b/drivers/power/supply/bq25890_charger.c @@ -650,7 +650,7 @@ static void bq25890_charger_external_power_changed(struct power_supply *psy) if (bq->chip_version != BQ25892) return; - ret = power_supply_get_property_from_supplier(bq->charger, + ret = power_supply_get_property_from_supplier(psy, POWER_SUPPLY_PROP_USB_TYPE, &val); if (ret) |