From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: linux-rtc@vger.kernel.org
Cc: Fabio Estevam <fabio.estevam@nxp.com>,
Anson Huang <Anson.Huang@nxp.com>,
linux-kernel@vger.kernel.org,
Alexandre Belloni <alexandre.belloni@bootlin.com>
Subject: [PATCH 1/3] rtc: mxc: fix possible race condition
Date: Tue, 16 Apr 2019 10:30:43 +0200 [thread overview]
Message-ID: <20190416083045.13924-1-alexandre.belloni@bootlin.com> (raw)
The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler. This may lead to a NULL pointer
dereference.
Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
struct before requesting the IRQ.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
drivers/rtc/rtc-mxc.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 708b9e9b86a6..d9a038afedf0 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -340,6 +340,13 @@ static int mxc_rtc_probe(struct platform_device *pdev)
if (IS_ERR(pdata->ioaddr))
return PTR_ERR(pdata->ioaddr);
+ rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(rtc))
+ return PTR_ERR(rtc);
+
+ pdata->rtc = rtc;
+ rtc->ops = &mxc_rtc_ops;
+
pdata->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(pdata->clk_ipg)) {
dev_err(&pdev->dev, "unable to get ipg clock!\n");
@@ -402,14 +409,9 @@ static int mxc_rtc_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "failed to enable irq wake\n");
}
- rtc = devm_rtc_device_register(&pdev->dev, pdev->name, &mxc_rtc_ops,
- THIS_MODULE);
- if (IS_ERR(rtc)) {
- ret = PTR_ERR(rtc);
+ ret = rtc_register_device(rtc);
+ if (ret)
goto exit_put_clk_ref;
- }
-
- pdata->rtc = rtc;
return 0;
--
2.20.1
next reply other threads:[~2019-04-16 8:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-16 8:30 Alexandre Belloni [this message]
2019-04-16 8:30 ` [PATCH 2/3] rtc: mxc: set range Alexandre Belloni
2019-04-16 8:30 ` [PATCH 3/3] rtc: mxc: use .set_time Alexandre Belloni
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