From: Waqar Hameed Date: Sat, 20 Dec 2025 22:36:01 +0000 (+0100) Subject: power: supply: pf1550: Fix use-after-free in power_supply_changed() X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=838767f5074700552d3f006d867caed65edc7328;p=thirdparty%2Flinux.git power: supply: pf1550: 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: 4b6b6433a97d ("power: supply: pf1550: add battery charger support") Signed-off-by: Waqar Hameed Reviewed-by: Samuel Kayode Link: https://patch.msgid.link/ae5a71b7e4dd2967d8fdcc531065cc71b17c86f5.1766268280.git.waqar.hameed@axis.com Signed-off-by: Sebastian Reichel --- diff --git a/drivers/power/supply/pf1550-charger.c b/drivers/power/supply/pf1550-charger.c index 98f1ee8eca3bc..a457862ef4610 100644 --- a/drivers/power/supply/pf1550-charger.c +++ b/drivers/power/supply/pf1550-charger.c @@ -584,22 +584,6 @@ static int pf1550_charger_probe(struct platform_device *pdev) return dev_err_probe(chg->dev, ret, "failed to add battery sense work\n"); - for (i = 0; i < PF1550_CHARGER_IRQ_NR; i++) { - irq = platform_get_irq(pdev, i); - if (irq < 0) - return irq; - - chg->virqs[i] = irq; - - ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, - pf1550_charger_irq_handler, - IRQF_NO_SUSPEND, - "pf1550-charger", chg); - if (ret) - return dev_err_probe(&pdev->dev, ret, - "failed irq request\n"); - } - psy_cfg.drv_data = chg; chg->charger = devm_power_supply_register(&pdev->dev, @@ -616,6 +600,22 @@ static int pf1550_charger_probe(struct platform_device *pdev) return dev_err_probe(&pdev->dev, PTR_ERR(chg->battery), "failed: power supply register\n"); + for (i = 0; i < PF1550_CHARGER_IRQ_NR; i++) { + irq = platform_get_irq(pdev, i); + if (irq < 0) + return irq; + + chg->virqs[i] = irq; + + ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, + pf1550_charger_irq_handler, + IRQF_NO_SUSPEND, + "pf1550-charger", chg); + if (ret) + return dev_err_probe(&pdev->dev, ret, + "failed irq request\n"); + } + pf1550_dt_parse_dev_info(chg); return pf1550_reg_init(chg);