[PATCH 4.19 170/264] pwm: img: Fix null pointer access in probe

Greg Kroah-Hartman
2020-10-27T17:51:36Z

From: Hauke Mehrtens <hauke@hauke-m.de>

[ Upstream commit b39c0615d0667b3a6f2f5c4bf99ffadf3b518bb1 ]

dev_get_drvdata() is called in img_pwm_runtime_resume() before the
driver data is set.
When pm_runtime_enabled() returns false in img_pwm_probe() it calls
img_pwm_runtime_resume() which results in a null pointer access.

This patch fixes the problem by setting the driver data earlier in the
img_pwm_probe() function.

This crash was seen when booting the Imagination Technologies Creator
Ci40 (Marduk) with kernel 5.4 in OpenWrt.

Fixes: e690ae526216 ("pwm: img: Add runtime PM")
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pwm/pwm-img.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c
index da72b2866e88e..3b0a097ce2abd 100644
--- a/drivers/pwm/pwm-img.c
+++ b/drivers/pwm/pwm-img.c
@@ -280,6 +280,8 @@ static int img_pwm_probe(struct platform_device *pdev)
return PTR_ERR(pwm->pwm_clk);
}

+ platform_set_drvdata(pdev, pwm);
+
pm_runtime_set_autosuspend_delay(&pdev->dev, IMG_PWM_PM_TIMEOUT);
pm_runtime_use_autosuspend(&pdev->dev);
pm_runtime_enable(&pdev->dev);
@@ -316,7 +318,6 @@ static int img_pwm_probe(struct platform_device *pdev)
goto err_suspend;
}

- platform_set_drvdata(pdev, pwm);
return 0;

err_suspend:
--
2.25.1