From 5a74ca9a9b63eb50cefb316aabfcee6007c3d62f Mon Sep 17 00:00:00 2001 From: Alexandre Belloni Date: Wed, 20 Mar 2019 13:32:27 +0100 Subject: [PATCH] rtc: xgene: fix possible race condition BugLink: https://bugs.launchpad.net/bugs/1837517 [ Upstream commit a652e00ee1233e251a337c28e18a1da59224e5ce ] 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 Signed-off-by: Sasha Levin Signed-off-by: Khalid Elmously Signed-off-by: Stefan Bader --- drivers/rtc/rtc-xgene.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/rtc/rtc-xgene.c b/drivers/rtc/rtc-xgene.c index 153820876a82..2f741f455c30 100644 --- a/drivers/rtc/rtc-xgene.c +++ b/drivers/rtc/rtc-xgene.c @@ -168,6 +168,10 @@ static int xgene_rtc_probe(struct platform_device *pdev) if (IS_ERR(pdata->csr_base)) return PTR_ERR(pdata->csr_base); + pdata->rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(pdata->rtc)) + return PTR_ERR(pdata->rtc); + irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "No IRQ resource\n"); @@ -198,15 +202,15 @@ static int xgene_rtc_probe(struct platform_device *pdev) return ret; } - pdata->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, - &xgene_rtc_ops, THIS_MODULE); - if (IS_ERR(pdata->rtc)) { - clk_disable_unprepare(pdata->clk); - return PTR_ERR(pdata->rtc); - } - /* HW does not support update faster than 1 seconds */ pdata->rtc->uie_unsupported = 1; + pdata->rtc->ops = &xgene_rtc_ops; + + ret = rtc_register_device(pdata->rtc); + if (ret) { + clk_disable_unprepare(pdata->clk); + return ret; + } return 0; } -- 2.39.5