rtc: msc313: fix NULL deref in shared IRQ handler at probe

msc313_rtc_probe() calls devm_request_irq() with IRQF_SHARED and
&pdev->dev as the cookie, but platform_set_drvdata() is only called
later after the clock setup. With a shared IRQ line, another device
on the same line can trigger the handler in that window. The
handler does dev_get_drvdata() on the cookie, gets NULL, and
dereferences priv->rtc_base in interrupt context.

Pass priv as the cookie directly so the handler reads it from
dev_id without the lookup, removing the dependency on probe order.

Fixes: be7d9c9161 ("rtc: Add support for the MSTAR MSC313 RTC")
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Link: https://patch.msgid.link/20260511032703.48262-1-sozdayvek@gmail.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Stepan Ionichev 2026-05-11 08:27:03 +05:00 committed by Alexandre Belloni
parent a50b23a57f
commit a369f48be8

View File

@ -160,7 +160,7 @@ static const struct rtc_class_ops msc313_rtc_ops = {
static irqreturn_t msc313_rtc_interrupt(s32 irq, void *dev_id)
{
struct msc313_rtc *priv = dev_get_drvdata(dev_id);
struct msc313_rtc *priv = dev_id;
u16 reg;
reg = readw(priv->rtc_base + REG_RTC_STATUS_INT);
@ -206,7 +206,7 @@ static int msc313_rtc_probe(struct platform_device *pdev)
priv->rtc_dev->range_max = U32_MAX;
ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED,
dev_name(&pdev->dev), &pdev->dev);
dev_name(&pdev->dev), priv);
if (ret) {
dev_err(dev, "Could not request IRQ\n");
return ret;