diff options
| author | Waqar Hameed <waqar.hameed@axis.com> | 2025-12-21 01:36:01 +0300 |
|---|---|---|
| committer | Sebastian Reichel <sebastian.reichel@collabora.com> | 2026-01-12 04:52:30 +0300 |
| commit | 62914959b35e9a1e29cc0f64cb8cfc5075a5366f (patch) | |
| tree | d95a3ba98ad7a5177413a9114b19ce1c93a78ea2 | |
| parent | 838767f5074700552d3f006d867caed65edc7328 (diff) | |
| download | linux-62914959b35e9a1e29cc0f64cb8cfc5075a5366f.tar.xz | |
power: supply: pm8916_bms_vm: 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: 098bce1838e0 ("power: supply: Add pm8916 VM-BMS support")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Reviewed-by: Nikita Travkin <nikita@trvn.ru>
Link: https://patch.msgid.link/2749c09ff81fcac87ae48147e216135450d8c067.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
| -rw-r--r-- | drivers/power/supply/pm8916_bms_vm.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/power/supply/pm8916_bms_vm.c b/drivers/power/supply/pm8916_bms_vm.c index 5120be086e6f..de5d571c03e2 100644 --- a/drivers/power/supply/pm8916_bms_vm.c +++ b/drivers/power/supply/pm8916_bms_vm.c @@ -167,15 +167,6 @@ static int pm8916_bms_vm_battery_probe(struct platform_device *pdev) if (ret < 0) return -EINVAL; - irq = platform_get_irq_byname(pdev, "fifo"); - if (irq < 0) - return irq; - - ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_bms_vm_fifo_update_done_irq, - IRQF_ONESHOT, "pm8916_vm_bms", bat); - if (ret) - return ret; - ret = regmap_bulk_read(bat->regmap, bat->reg + PM8916_PERPH_TYPE, &tmp, 2); if (ret) goto comm_error; @@ -220,6 +211,15 @@ static int pm8916_bms_vm_battery_probe(struct platform_device *pdev) if (ret) return dev_err_probe(dev, ret, "Unable to get battery info\n"); + irq = platform_get_irq_byname(pdev, "fifo"); + if (irq < 0) + return irq; + + ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_bms_vm_fifo_update_done_irq, + IRQF_ONESHOT, "pm8916_vm_bms", bat); + if (ret) + return ret; + platform_set_drvdata(pdev, bat); return 0; |