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| author | Waqar Hameed <waqar.hameed@axis.com> | 2025-12-21 01:35:59 +0300 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2026-01-12 04:52:29 +0300 |
| commit | 8005843369723d9c8975b7c4202d1b85d6125302 (patch) | |
| tree | 54149f222cb1194eb209e33afbfb6b4d27747d79 | |
| parent | 3291c51d4684d048dd2eb91b5b65fcfdaf72141f (diff) | |
| download | linux-8005843369723d9c8975b7c4202d1b85d6125302.tar.xz | |
power: supply: bq256xx: 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: 32e4978bb920 ("power: supply: bq256xx: Introduce the BQ256XX charger driver")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/39da6da8cc060fa0382ca859f65071e791cb6119.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/bq256xx_charger.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/power/supply/bq256xx_charger.c b/drivers/power/supply/bq256xx_charger.c index 3eb173394005..563f512709b3 100644 --- a/drivers/power/supply/bq256xx_charger.c +++ b/drivers/power/supply/bq256xx_charger.c @@ -1740,6 +1740,12 @@ static int bq256xx_probe(struct i2c_client *client) usb_register_notifier(bq->usb3_phy, &bq->usb_nb); } + ret = bq256xx_power_supply_init(bq, &psy_cfg, 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, bq256xx_irq_handler_thread, @@ -1752,12 +1758,6 @@ static int bq256xx_probe(struct i2c_client *client) } } - ret = bq256xx_power_supply_init(bq, &psy_cfg, dev); - if (ret) { - dev_err(dev, "Failed to register power supply\n"); - return ret; - } - ret = bq256xx_hw_init(bq); if (ret) { dev_err(dev, "Cannot initialize the chip.\n"); |