From c4af8a98bb52825a5331ae1d0604c0ea6956ba4b Mon Sep 17 00:00:00 2001 From: Waqar Hameed Date: Sat, 20 Dec 2025 23:35:58 +0100 Subject: [PATCH] power: supply: ab8500: 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()`. Commit 1c1f13a006ed ("power: supply: ab8500: Move to componentized binding") introduced this issue during a refactorization. Fix this racy use-after-free by making sure the IRQ is requested _after_ the registration of the `power_supply` handle. Fixes: 1c1f13a006ed ("power: supply: ab8500: Move to componentized binding") Signed-off-by: Waqar Hameed Reviewed-by: Linus Walleij Link: https://patch.msgid.link/ccf83a09942cb8dda3dff70b2682f2c2e9cb97f2.1766268280.git.waqar.hameed@axis.com Signed-off-by: Sebastian Reichel --- drivers/power/supply/ab8500_charger.c | 40 +++++++++++++-------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/drivers/power/supply/ab8500_charger.c b/drivers/power/supply/ab8500_charger.c index 5f4537766e5b9..1813fbdfa1c1f 100644 --- a/drivers/power/supply/ab8500_charger.c +++ b/drivers/power/supply/ab8500_charger.c @@ -3466,26 +3466,6 @@ static int ab8500_charger_probe(struct platform_device *pdev) return ret; } - /* Request interrupts */ - for (i = 0; i < ARRAY_SIZE(ab8500_charger_irq); i++) { - irq = platform_get_irq_byname(pdev, ab8500_charger_irq[i].name); - if (irq < 0) - return irq; - - ret = devm_request_threaded_irq(dev, - irq, NULL, ab8500_charger_irq[i].isr, - IRQF_SHARED | IRQF_NO_SUSPEND | IRQF_ONESHOT, - ab8500_charger_irq[i].name, di); - - if (ret != 0) { - dev_err(dev, "failed to request %s IRQ %d: %d\n" - , ab8500_charger_irq[i].name, irq, ret); - return ret; - } - dev_dbg(dev, "Requested %s IRQ %d: %d\n", - ab8500_charger_irq[i].name, irq, ret); - } - /* initialize lock */ spin_lock_init(&di->usb_state.usb_lock); mutex_init(&di->usb_ipt_crnt_lock); @@ -3614,6 +3594,26 @@ static int ab8500_charger_probe(struct platform_device *pdev) return PTR_ERR(di->usb_chg.psy); } + /* Request interrupts */ + for (i = 0; i < ARRAY_SIZE(ab8500_charger_irq); i++) { + irq = platform_get_irq_byname(pdev, ab8500_charger_irq[i].name); + if (irq < 0) + return irq; + + ret = devm_request_threaded_irq(dev, + irq, NULL, ab8500_charger_irq[i].isr, + IRQF_SHARED | IRQF_NO_SUSPEND | IRQF_ONESHOT, + ab8500_charger_irq[i].name, di); + + if (ret != 0) { + dev_err(dev, "failed to request %s IRQ %d: %d\n" + , ab8500_charger_irq[i].name, irq, ret); + return ret; + } + dev_dbg(dev, "Requested %s IRQ %d: %d\n", + ab8500_charger_irq[i].name, irq, ret); + } + /* * Check what battery we have, since we always have the USB * psy, use that as a handle. -- 2.47.3