diff options
| author | Waqar Hameed <waqar.hameed@axis.com> | 2025-12-20 23:36:01 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-02-26 15:01:15 -0800 |
| commit | d7d31fc99d248d5f47588f50dce5c7599c991c6a (patch) | |
| tree | 3d4f6a9b8072035d6b4e32d86d1b3412f24ec6ef /drivers/power | |
| parent | 17db6b3abd823c9fba3f3413c4f0f432d99d49dc (diff) | |
power: supply: pm8916_lbc: Fix use-after-free in power_supply_changed()
[ Upstream commit b7508129978ae1e2ed9b0410396abc05def9c4eb ]
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: f8d7a3d21160 ("power: supply: Add driver for pm8916 lbc")
Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Reviewed-by: Nikita Travkin <nikita@trvn.ru>
Link: https://patch.msgid.link/64d8dd3675a4e59fa32c3e0ef451f12d1f7ed18f.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/power')
| -rw-r--r-- | drivers/power/supply/pm8916_lbc.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/drivers/power/supply/pm8916_lbc.c b/drivers/power/supply/pm8916_lbc.c index c74b75b1b267..3ca717d84aad 100644 --- a/drivers/power/supply/pm8916_lbc.c +++ b/drivers/power/supply/pm8916_lbc.c @@ -274,15 +274,6 @@ static int pm8916_lbc_charger_probe(struct platform_device *pdev) return dev_err_probe(dev, -EINVAL, "Wrong amount of reg values: %d (4 expected)\n", len); - irq = platform_get_irq_byname(pdev, "usb_vbus"); - if (irq < 0) - return irq; - - ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_lbc_charger_state_changed_irq, - IRQF_ONESHOT, "pm8916_lbc", chg); - if (ret) - return ret; - ret = device_property_read_u32_array(dev, "reg", chg->reg, len); if (ret) return ret; @@ -332,6 +323,15 @@ static int pm8916_lbc_charger_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, "usb_vbus"); + if (irq < 0) + return irq; + + ret = devm_request_threaded_irq(dev, irq, NULL, pm8916_lbc_charger_state_changed_irq, + IRQF_ONESHOT, "pm8916_lbc", chg); + if (ret) + return ret; + chg->edev = devm_extcon_dev_allocate(dev, pm8916_lbc_charger_cable); if (IS_ERR(chg->edev)) return PTR_ERR(chg->edev); |