[PATCH AUTOSEL 5.3 21/49] rtc: snvs: fix possible race condition
From: Sasha Levin <sashal@kernel.org>
Date: 2019-09-29 17:43:10
Also in:
lkml, stable
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
From: Anson Huang <redacted> [ Upstream commit 6fd4fe9b496d9ba3382992ff4fde3871d1b6f63d ] 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 <redacted> Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com> Link: https://lore.kernel.org/r/20190716071858.36750-1-Anson.Huang@nxp.com (local) Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/rtc/rtc-snvs.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index 7ee673a25fd0a..4f9a107a04277 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; }
--
2.20.1