[PATCH] power: supply: lp8788-charger: fix use-after-free on remove

Fan Wu posted 1 patch 2 months ago
drivers/power/supply/lp8788-charger.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[PATCH] power: supply: lp8788-charger: fix use-after-free on remove
Posted by Fan Wu 2 months ago
lp8788_charger_remove() flushes charger_work before unregistering the
IRQs. An IRQ thread can queue charger_work after flush_work() has
returned. The work can then run after devres frees pchg and dereference
it in lp8788_charger_event().

Unregister the IRQs first. free_irq() waits for any running threaded
handler, so no handler can queue more work afterwards. Then use
cancel_work_sync() to cancel pending work or wait for running work to
finish.

This issue was found by an in-house static analysis tool.

Fixes: 98a276649358 ("power_supply: Add new lp8788 charger driver")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6
Signed-off-by: Fan Wu <fanwu01@zju.edu.cn>

---
 drivers/power/supply/lp8788-charger.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/power/supply/lp8788-charger.c b/drivers/power/supply/lp8788-charger.c
index f0a680c155..1bc2c150fb 100644
--- a/drivers/power/supply/lp8788-charger.c
+++ b/drivers/power/supply/lp8788-charger.c
@@ -710,8 +710,8 @@ static void lp8788_charger_remove(struct platform_device *pdev)
 {
 	struct lp8788_charger *pchg = platform_get_drvdata(pdev);

-	flush_work(&pchg->charger_work);
 	lp8788_irq_unregister(pdev, pchg);
+	cancel_work_sync(&pchg->charger_work);
 }

 static struct platform_driver lp8788_charger_driver = {
--
2.43.0
Re: [PATCH] power: supply: lp8788-charger: fix use-after-free on remove
Posted by Sebastian Reichel 1 month, 4 weeks ago
On Sun, 02 Aug 2026 03:54:42 +0000, Fan Wu wrote:
> lp8788_charger_remove() flushes charger_work before unregistering the
> IRQs. An IRQ thread can queue charger_work after flush_work() has
> returned. The work can then run after devres frees pchg and dereference
> it in lp8788_charger_event().
> 
> Unregister the IRQs first. free_irq() waits for any running threaded
> handler, so no handler can queue more work afterwards. Then use
> cancel_work_sync() to cancel pending work or wait for running work to
> finish.
> 
> [...]

Applied, thanks!

[1/1] power: supply: lp8788-charger: fix use-after-free on remove
      commit: 831c29a12d560f8a3225f43050b3fbb5dfd79c66

Best regards,
-- 
Sebastian Reichel <sebastian.reichel@collabora.com>