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 | 642f33e34b969eedec334738fd5df95d2dc42742 (patch) | |
| tree | 892d3adecd59d22821c1242aea8f80ad0f18580e | |
| parent | 5f0b1cb41906e86b64bf69f5ededb83b0d757c27 (diff) | |
| download | linux-642f33e34b969eedec334738fd5df95d2dc42742.tar.xz | |
power: supply: cpcap-battery: 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: 874b2adbed12 ("power: supply: cpcap-battery: Add a battery driver")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/81db58d610c9a51a68184f856cd431a934cccee2.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/cpcap-battery.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/power/supply/cpcap-battery.c b/drivers/power/supply/cpcap-battery.c index 8106d1edcbc2..507fdc1c866d 100644 --- a/drivers/power/supply/cpcap-battery.c +++ b/drivers/power/supply/cpcap-battery.c @@ -1122,10 +1122,6 @@ static int cpcap_battery_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ddata); - error = cpcap_battery_init_interrupts(pdev, ddata); - if (error) - return error; - error = cpcap_battery_init_iio(ddata); if (error) return error; @@ -1142,6 +1138,10 @@ static int cpcap_battery_probe(struct platform_device *pdev) return error; } + error = cpcap_battery_init_interrupts(pdev, ddata); + if (error) + return error; + atomic_set(&ddata->active, 1); error = cpcap_battery_calibrate(ddata); |