diff options
| author | Waqar Hameed <waqar.hameed@axis.com> | 2025-12-21 01:36:00 +0300 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2026-01-12 04:52:30 +0300 |
| commit | b2ce982e2e0c888dc55c888ad0e20ea04daf2e6b (patch) | |
| tree | 4242ce4eee57c71bc92dff0822aab51168112db9 | |
| parent | 642f33e34b969eedec334738fd5df95d2dc42742 (diff) | |
| download | linux-b2ce982e2e0c888dc55c888ad0e20ea04daf2e6b.tar.xz | |
power: supply: goldfish: 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: 84d7b7687489 ("power: Add battery driver for goldfish emulator")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/500a606bb6fb6f2bb8d797e19a00cea9dd7b03c1.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/goldfish_battery.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/power/supply/goldfish_battery.c b/drivers/power/supply/goldfish_battery.c index 479195e35d73..5aa24e4dc445 100644 --- a/drivers/power/supply/goldfish_battery.c +++ b/drivers/power/supply/goldfish_battery.c @@ -224,12 +224,6 @@ static int goldfish_battery_probe(struct platform_device *pdev) if (data->irq < 0) return -ENODEV; - ret = devm_request_irq(&pdev->dev, data->irq, - goldfish_battery_interrupt, - IRQF_SHARED, pdev->name, data); - if (ret) - return ret; - psy_cfg.drv_data = data; data->ac = devm_power_supply_register(&pdev->dev, @@ -244,6 +238,12 @@ static int goldfish_battery_probe(struct platform_device *pdev) if (IS_ERR(data->battery)) return PTR_ERR(data->battery); + ret = devm_request_irq(&pdev->dev, data->irq, + goldfish_battery_interrupt, + IRQF_SHARED, pdev->name, data); + if (ret) + return ret; + GOLDFISH_BATTERY_WRITE(data, BATTERY_INT_ENABLE, BATTERY_INT_MASK); return 0; } |