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| author | Waqar Hameed <waqar.hameed@axis.com> | 2025-12-20 23:36:02 +0100 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2026-01-12 02:52:31 +0100 |
| commit | e2febe375e5ea5afed92f4cd9711bde8f24ee6d2 (patch) | |
| tree | 42cfa583861172656d658a94142b2f19e26b2232 | |
| parent | b7508129978ae1e2ed9b0410396abc05def9c4eb (diff) | |
| download | linux-e2febe375e5ea5afed92f4cd9711bde8f24ee6d2.tar.gz linux-e2febe375e5ea5afed92f4cd9711bde8f24ee6d2.zip | |
power: supply: rt9455: 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: e86d69dd786e ("power_supply: Add support for Richtek RT9455 battery charger")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/1567d831e04c3e2fcb9e18dd36b7bcba4634581a.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/rt9455_charger.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/power/supply/rt9455_charger.c b/drivers/power/supply/rt9455_charger.c index 1ffe7f02932f..5130d2395e88 100644 --- a/drivers/power/supply/rt9455_charger.c +++ b/drivers/power/supply/rt9455_charger.c @@ -1663,6 +1663,15 @@ static int rt9455_probe(struct i2c_client *client) rt9455_charger_config.supplied_to = rt9455_charger_supplied_to; rt9455_charger_config.num_supplicants = ARRAY_SIZE(rt9455_charger_supplied_to); + + info->charger = devm_power_supply_register(dev, &rt9455_charger_desc, + &rt9455_charger_config); + if (IS_ERR(info->charger)) { + dev_err(dev, "Failed to register charger\n"); + ret = PTR_ERR(info->charger); + goto put_usb_notifier; + } + ret = devm_request_threaded_irq(dev, client->irq, NULL, rt9455_irq_handler_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT, @@ -1678,14 +1687,6 @@ static int rt9455_probe(struct i2c_client *client) goto put_usb_notifier; } - info->charger = devm_power_supply_register(dev, &rt9455_charger_desc, - &rt9455_charger_config); - if (IS_ERR(info->charger)) { - dev_err(dev, "Failed to register charger\n"); - ret = PTR_ERR(info->charger); - goto put_usb_notifier; - } - return 0; put_usb_notifier: |