[PATCH 6.19 453/781] power: supply: pf1550: Fix use-after-free in power_supply_changed()

Greg Kroah-Hartman
2026-02-25T01:35:19Z

From: Waqar Hameed <waqar.hameed@axis.com>

[ Upstream commit 838767f5074700552d3f006d867caed65edc7328 ]

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 <waqar.hameed@axis.com>
Reviewed-by: Samuel Kayode <samkay014@gmail.com>
Link: https://patch.msgid.link/ae5a71b7e4dd2967d8fdcc531065cc71b17c86f5.1766268280.git.waqar.hameed@axis.com
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/power/supply/pf1550-charger.c | 32 +++++++++++++--------------
1 file changed, 16 insertions(+), 16 deletions(-)

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);
--
2.51.0