From 5f0b1cb41906e86b64bf69f5ededb83b0d757c27 Mon Sep 17 00:00:00 2001 From: Waqar Hameed Date: Sat, 20 Dec 2025 23:35:59 +0100 Subject: [PATCH] power: supply: bq25980: Fix use-after-free in power_supply_changed() Using the `devm_` variant for requesting IRQ _before_ the `devm_` variant for allocating/registering the `power_supply` handle, means that the `power_supply` handle will be deallocated/unregistered _before_ the interrupt handler (since `devm_` naturally deallocates in reverse allocation order). This means that during removal, there is a race condition where an interrupt can fire just _after_ the `power_supply` handle has been freed, *but* just _before_ the corresponding unregistration of the IRQ handler has run. This will lead to the IRQ handler calling `power_supply_changed()` with a freed `power_supply` handle. Which usually crashes the system or otherwise silently corrupts the memory... Note that there is a similar situation which can also happen during `probe()`; the possibility of an interrupt firing _before_ registering the `power_supply` handle. This would then lead to the nasty situation of using the `power_supply` handle *uninitialized* in `power_supply_changed()`. Fix this racy use-after-free by making sure the IRQ is requested _after_ the registration of the `power_supply` handle. Fixes: 5069185fc18e ("power: supply: bq25980: Add support for the BQ259xx family") Signed-off-by: Waqar Hameed Link: https://patch.msgid.link/8763035cadb959e14787b3837f2d3db61f6e1c34.1766268280.git.waqar.hameed@axis.com Signed-off-by: Sebastian Reichel --- drivers/power/supply/bq25980_charger.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/power/supply/bq25980_charger.c b/drivers/power/supply/bq25980_charger.c index 4f91fd1a3dec..44af3a0c92e5 100644 --- a/drivers/power/supply/bq25980_charger.c +++ b/drivers/power/supply/bq25980_charger.c @@ -1240,6 +1240,12 @@ static int bq25980_probe(struct i2c_client *client) return ret; } + ret = bq25980_power_supply_init(bq, dev); + if (ret) { + dev_err(dev, "Failed to register power supply\n"); + return ret; + } + if (client->irq) { ret = devm_request_threaded_irq(dev, client->irq, NULL, bq25980_irq_handler_thread, @@ -1250,12 +1256,6 @@ static int bq25980_probe(struct i2c_client *client) return ret; } - ret = bq25980_power_supply_init(bq, dev); - if (ret) { - dev_err(dev, "Failed to register power supply\n"); - return ret; - } - ret = bq25980_hw_init(bq); if (ret) { dev_err(dev, "Cannot initialize the chip.\n"); -- 2.47.3