[PATCH v2 -next] usb/usbip: fix wrong data added to platform device

[Hongren Zheng <i@zenithal.me>]

.data of platform_device_info will be copied into .platform_data of
struct device via platform_device_add_data.

However, vhcis[i] contains a spinlock, is dynamically allocated and
used by other code, so it is not meant to be copied. The workaround
was to use void *vhci as an agent, but it was removed in the commit
suggested below.

This patch adds back the workaround and changes the way of using
platform_data accordingly.

Reported-by: syzbot+e0dbc33630a092ccf033@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/00000000000029242706077f3145@google.com/
Reported-by: syzbot+6867a9777f4b8dc4e256@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/0000000000007634c1060793197c@google.com/
Fixes: b8aaf639b403 ("usbip: Use platform_device_register_full()")
Tested-by: syzbot+6867a9777f4b8dc4e256@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/0000000000007ac87d0607979b6b@google.com/
Signed-off-by: Hongren Zheng <i@zenithal.me>
---
 drivers/usb/usbip/vhci_hcd.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

v2:
code style change suggested by Andy Shevchenko

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index f845b91848b9..82650c11e451 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1139,7 +1139,7 @@ static int hcd_name_to_id(const char *name)
 
 static int vhci_setup(struct usb_hcd *hcd)
 {
-	struct vhci *vhci = dev_get_platdata(hcd->self.controller);
+	struct vhci *vhci = *((void **)dev_get_platdata(hcd->self.controller));
 
 	if (usb_hcd_is_primary_hcd(hcd)) {
 		vhci->vhci_hcd_hs = hcd_to_vhci_hcd(hcd);
@@ -1257,7 +1257,7 @@ static int vhci_get_frame_number(struct usb_hcd *hcd)
 /* FIXME: suspend/resume */
 static int vhci_bus_suspend(struct usb_hcd *hcd)
 {
-	struct vhci *vhci = dev_get_platdata(hcd->self.controller);
+	struct vhci *vhci = *((void **)dev_get_platdata(hcd->self.controller));
 	unsigned long flags;
 
 	dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
@@ -1271,7 +1271,7 @@ static int vhci_bus_suspend(struct usb_hcd *hcd)
 
 static int vhci_bus_resume(struct usb_hcd *hcd)
 {
-	struct vhci *vhci = dev_get_platdata(hcd->self.controller);
+	struct vhci *vhci = *((void **)dev_get_platdata(hcd->self.controller));
 	int rc = 0;
 	unsigned long flags;
 
@@ -1338,7 +1338,7 @@ static const struct hc_driver vhci_hc_driver = {
 
 static int vhci_hcd_probe(struct platform_device *pdev)
 {
-	struct vhci             *vhci = dev_get_platdata(&pdev->dev);
+	struct vhci             *vhci = *((void **)dev_get_platdata(&pdev->dev));
 	struct usb_hcd		*hcd_hs;
 	struct usb_hcd		*hcd_ss;
 	int			ret;
@@ -1396,7 +1396,7 @@ static int vhci_hcd_probe(struct platform_device *pdev)
 
 static void vhci_hcd_remove(struct platform_device *pdev)
 {
-	struct vhci *vhci = dev_get_platdata(&pdev->dev);
+	struct vhci *vhci = *((void **)dev_get_platdata(&pdev->dev));
 
 	/*
 	 * Disconnects the root hub,
@@ -1431,7 +1431,7 @@ static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
 	if (!hcd)
 		return 0;
 
-	vhci = dev_get_platdata(hcd->self.controller);
+	vhci = *((void **)dev_get_platdata(hcd->self.controller));
 
 	spin_lock_irqsave(&vhci->lock, flags);
 
@@ -1522,10 +1522,11 @@ static int __init vhci_hcd_init(void)
 		goto err_driver_register;
 
 	for (i = 0; i < vhci_num_controllers; i++) {
+		void *vhci = &vhcis[i];
 		struct platform_device_info pdevinfo = {
 			.name = driver_name,
 			.id = i,
-			.data = &vhcis[i],
+			.data = &vhci,
 			.size_data = sizeof(void *),
 		};
 
-- 
2.37.2