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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 | 3291c51d4684d048dd2eb91b5b65fcfdaf72141f (patch) | |
| tree | 456ef04973075fcee712db6d5f068e5a6f6de05b | |
| parent | c4af8a98bb52825a5331ae1d0604c0ea6956ba4b (diff) | |
| download | linux-3291c51d4684d048dd2eb91b5b65fcfdaf72141f.tar.xz | |
power: supply: act8945a: 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: a09209acd6a8 ("power: supply: act8945a_charger: Add status change update support")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/bcf3a23b5187df0bba54a8c8fe09f8b8a0031dee.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/act8945a_charger.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/drivers/power/supply/act8945a_charger.c b/drivers/power/supply/act8945a_charger.c index 3901a02f326a..9dec4486b143 100644 --- a/drivers/power/supply/act8945a_charger.c +++ b/drivers/power/supply/act8945a_charger.c @@ -597,14 +597,6 @@ static int act8945a_charger_probe(struct platform_device *pdev) return irq ?: -ENXIO; } - ret = devm_request_irq(&pdev->dev, irq, act8945a_status_changed, - IRQF_TRIGGER_FALLING, "act8945a_interrupt", - charger); - if (ret) { - dev_err(&pdev->dev, "failed to request nIRQ pin IRQ\n"); - return ret; - } - charger->desc.name = "act8945a-charger"; charger->desc.get_property = act8945a_charger_get_property; charger->desc.properties = act8945a_charger_props; @@ -625,6 +617,14 @@ static int act8945a_charger_probe(struct platform_device *pdev) return PTR_ERR(charger->psy); } + ret = devm_request_irq(&pdev->dev, irq, act8945a_status_changed, + IRQF_TRIGGER_FALLING, "act8945a_interrupt", + charger); + if (ret) { + dev_err(&pdev->dev, "failed to request nIRQ pin IRQ\n"); + return ret; + } + platform_set_drvdata(pdev, charger); INIT_WORK(&charger->work, act8945a_work); |