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authorAnson Huang <Anson.Huang@nxp.com>2019-07-16 09:18:58 +0200
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-08-29 17:53:12 +0200
commit6fd4fe9b496d9ba3382992ff4fde3871d1b6f63d (patch)
tree41aa0933b5122855eb9c52d516e0eb362c6497ab /drivers/rtc
parentrtc: pcf2127: bugfix: watchdog build dependency (diff)
downloadlinux-6fd4fe9b496d9ba3382992ff4fde3871d1b6f63d.tar.xz
linux-6fd4fe9b496d9ba3382992ff4fde3871d1b6f63d.zip
rtc: snvs: fix possible race condition
The RTC IRQ is requested before the struct rtc_device is allocated, this may lead to a NULL pointer dereference in IRQ handler. To fix this issue, allocating the rtc_device struct before requesting the RTC IRQ using devm_rtc_allocate_device, and use rtc_register_device to register the RTC device. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Link: https://lore.kernel.org/r/20190716071858.36750-1-Anson.Huang@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-snvs.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index 7ee673a25fd0..4f9a107a0427 100644
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -279,6 +279,10 @@ static int snvs_rtc_probe(struct platform_device *pdev)
if (!data)
return -ENOMEM;
+ data->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(data->rtc))
+ return PTR_ERR(data->rtc);
+
data->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
if (IS_ERR(data->regmap)) {
@@ -343,10 +347,9 @@ static int snvs_rtc_probe(struct platform_device *pdev)
goto error_rtc_device_register;
}
- data->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
- &snvs_rtc_ops, THIS_MODULE);
- if (IS_ERR(data->rtc)) {
- ret = PTR_ERR(data->rtc);
+ data->rtc->ops = &snvs_rtc_ops;
+ ret = rtc_register_device(data->rtc);
+ if (ret) {
dev_err(&pdev->dev, "failed to register rtc: %d\n", ret);
goto error_rtc_device_register;
}