Input: max8997-haptic - fix NULL pointer dereference

6ae645d5 · Marek Szyprowski <[email protected]> · 2016-05-09 09:31:47 -07:00

NULL pointer derefence happens when booting with DTB because the
platform data for haptic device is not set in supplied data from parent
MFD device.

The MFD device creates only platform data (from Device Tree) for itself,
not for haptic child.

Unable to handle kernel NULL pointer dereference at virtual address 0000009c
pgd = c0004000
	[0000009c] *pgd=00000000
	Internal error: Oops: 5 [#1] PREEMPT SMP ARM
	(max8997_haptic_probe) from [<c03f9cec>] (platform_drv_probe+0x4c/0xb0)
	(platform_drv_probe) from [<c03f8440>] (driver_probe_device+0x214/0x2c0)
	(driver_probe_device) from [<c03f8598>] (__driver_attach+0xac/0xb0)
	(__driver_attach) from [<c03f67ac>] (bus_for_each_dev+0x68/0x9c)
	(bus_for_each_dev) from [<c03f7a38>] (bus_add_driver+0x1a0/0x218)
	(bus_add_driver) from [<c03f8db0>] (driver_register+0x78/0xf8)
	(driver_register) from [<c0101774>] (do_one_initcall+0x90/0x1d8)
	(do_one_initcall) from [<c0a00dbc>] (kernel_init_freeable+0x15c/0x1fc)
	(kernel_init_freeable) from [<c06bb5b4>] (kernel_init+0x8/0x114)
	(kernel_init) from [<c0107938>] (ret_from_fork+0x14/0x3c)

Signed-off-by: Marek Szyprowski <[email protected]>
Cc: <[email protected]>
Fixes: 104594b01ce7 ("Input: add driver support for MAX8997-haptic")
[k.kozlowski: Write commit message, add CC-stable]
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>

Commit: 6ae645d5fa385f3787bf1723639cd907fe5865e7
Parents: 82aaa086

Changes

1 files changed · +4 −2

File	Status	Add	Del	Content
drivers/input/misc/max8997_haptic.c	modified	+4	−2	View file

drivers/input/misc/max8997_haptic.c

View file

diff --git a/drivers/input/misc/max8997_haptic.c b/drivers/input/misc/max8997_haptic.c
index a806ba3..8d6326d 100644
--- a/drivers/input/misc/max8997_haptic.c
+++ b/drivers/input/misc/max8997_haptic.c
@@ -255,12 +255,14 @@ static int max8997_haptic_probe(struct platform_device *pdev)
 	struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
 	const struct max8997_platform_data *pdata =
 					dev_get_platdata(iodev->dev);
-	const struct max8997_haptic_platform_data *haptic_pdata =
-					pdata->haptic_pdata;
+	const struct max8997_haptic_platform_data *haptic_pdata = NULL;
 	struct max8997_haptic *chip;
 	struct input_dev *input_dev;
 	int error;
 
+	if (pdata)
+		haptic_pdata = pdata->haptic_pdata;
+
 	if (!haptic_pdata) {
 		dev_err(&pdev->dev, "no haptic platform data\n");
 		return -EINVAL;