6.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
[ Upstream commit 3dc0bab23dba53f315c9a7b4a679e0a6d46f7c6e ]
power_supply_uevent() which is called to emit a udev event on device
deletion attempts to use the power_supply_battery_info structure,
which is device-managed and has been freed before this point.
Fix this by not generating all battery/charger properties when the
device is about to be removed. This also avoids generating errors
when trying to access the hardware in hot-unplug scenarios.
==================================================================
BUG: KASAN: slab-use-after-free in power_supply_battery_info_has_prop (power_supply_core.c:872)
Read of size 4 at addr 0000000062e59028 by task python3/27
Call Trace:
power_supply_battery_info_has_prop (power_supply_core.c:872)
power_supply_uevent (power_supply_sysfs.c:504)
dev_uevent (drivers/base/core.c:2590)
kobject_uevent_env (lib/kobject_uevent.c:558)
kobject_uevent (lib/kobject_uevent.c:643)
device_del (drivers/base/core.c:3266 drivers/base/core.c:3831)
device_unregister (drivers/base/core.c:3730 drivers/base/core.c:3854)
power_supply_unregister (power_supply_core.c:1608)
devm_power_supply_release (power_supply_core.c:1515)
release_nodes (drivers/base/devres.c:506)
devres_release_group (drivers/base/devres.c:669)
i2c_device_remove (drivers/i2c/i2c-core-base.c:629)
device_remove (drivers/base/dd.c:570)
device_release_driver_internal (drivers/base/dd.c:1274 drivers/base/dd.c:1295)
device_driver_detach (drivers/base/dd.c:1332)
unbind_store (drivers/base/bus.c:247)
...
Allocated by task 27:
devm_kmalloc (drivers/base/devres.c:119 drivers/base/devres.c:829)
power_supply_get_battery_info (include/linux/device.h:316 power_supply_core.c:626)
__power_supply_register (power_supply_core.c:1408)
devm_power_supply_register (power_supply_core.c:1544)
bq256xx_probe (bq256xx_charger.c:1539 bq256xx_charger.c:1727) bq256xx_charger
i2c_device_probe (drivers/i2c/i2c-core-base.c:584)
really_probe (drivers/base/dd.c:579 drivers/base/dd.c:658)
__driver_probe_device (drivers/base/dd.c:800)
device_driver_attach (drivers/base/dd.c:1128)
bind_store (drivers/base/bus.c:273)
...
Freed by task 27:
kfree (mm/slab_common.c:1073)
release_nodes (drivers/base/devres.c:503)
devres_release_all (drivers/base/devres.c:536)
device_del (drivers/base/core.c:3829)
device_unregister (drivers/base/core.c:3730 drivers/base/core.c:3854)
power_supply_unregister (power_supply_core.c:1608)
devm_power_supply_release (power_supply_core.c:1515)
release_nodes (drivers/base/devres.c:506)
devres_release_group (drivers/base/devres.c:669)
i2c_device_remove (drivers/i2c/i2c-core-base.c:629)
device_remove (drivers/base/dd.c:570)
device_release_driver_internal (drivers/base/dd.c:1274 drivers/base/dd.c:1295)
device_driver_detach (drivers/base/dd.c:1332)
unbind_store (drivers/base/bus.c:247)
...
==================================================================
Reported-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Fixes: 27a2195efa8d ("power: supply: core: auto-exposure of simple-battery data")
Tested-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/power/supply/power_supply_sysfs.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index 06e5b6b0e255c..d483a81560ab0 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -482,6 +482,13 @@ int power_supply_uevent(const struct device *dev, struct kobj_uevent_env *env)
if (ret)
return ret;
+ /*
+ * Kernel generates KOBJ_REMOVE uevent in device removal path, after
+ * resources have been freed. Exit early to avoid use-after-free.
+ */
+ if (psy->removing)
+ return 0;
+
prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
if (!prop_buf)
return -ENOMEM;
--
2.40.1
