diff mbox series

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

Message ID ZSkhWa5wmAGsAdCK@Sun
State New
Headers
Series [-next] usb/usbip: fix wrong data added to platform device |

Commit Message

Hongren Zheng Oct. 13, 2023, 10:52 a.m. UTC 
  .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/linux-usb/00000000000029242706077f3145@google.com/
Reported-by: syzbot+6867a9777f4b8dc4e256@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-usb/0000000000007634c1060793197c@google.com/
Fixes: b8aaf639b403 ("usbip: Use platform_device_register_full()")
Signed-off-by: Hongren Zheng <i@zenithal.me>
---
 drivers/usb/usbip/vhci_hcd.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

Comments

Hongren Zheng Oct. 13, 2023, 12:05 p.m. UTC | #1 
On Fri, Oct 13, 2023 at 06:52:09PM +0800, Hongren Zheng wrote:
> .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/linux-usb/00000000000029242706077f3145@google.com/
> Reported-by: syzbot+6867a9777f4b8dc4e256@syzkaller.appspotmail.com
> Closes: https://lore.kernel.org/linux-usb/0000000000007634c1060793197c@google.com/
> Fixes: b8aaf639b403 ("usbip: Use platform_device_register_full()")
> Signed-off-by: Hongren Zheng <i@zenithal.me>
> ---

Tested-by: syzbot+6867a9777f4b8dc4e256@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/0000000000007ac87d0607979b6b@google.com/
Andy Shevchenko Oct. 13, 2023, 7:55 p.m. UTC | #2 
On Fri, Oct 13, 2023 at 06:52:09PM +0800, Hongren Zheng wrote:
> .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.

Thanks for fixing this.

...

> -	struct vhci *vhci = dev_get_platdata(hcd->self.controller);

> -

The blank line here is on purpose.

> +	struct vhci *vhci = *((void **)dev_get_platdata(hcd->self.controller));
Andy Shevchenko Oct. 13, 2023, 7:58 p.m. UTC | #3 
On Fri, Oct 13, 2023 at 06:52:09PM +0800, Hongren Zheng wrote:
> .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.

...


One more thing...

>  static int __init vhci_hcd_init(void)
>  {
>  	int i, ret;
> +	void *vhci;
>  
>  	if (usb_disabled())
>  		return -ENODEV;
> @@ -1522,10 +1522,11 @@ static int __init vhci_hcd_init(void)
>  		goto err_driver_register;
>  
>  	for (i = 0; i < vhci_num_controllers; i++) {

> +		vhci = &vhcis[i];

This should be

		void *vhci = &vhcis[i];

because otherwise we mix code and definitions which is not so good style. (Yet
we allow to do that in exceptional cases: 1) iterators in for-loops, and 2)
RAII allocations with __free() in use.)

>  		struct platform_device_info pdevinfo = {
>  			.name = driver_name,
>  			.id = i,
> -			.data = &vhcis[i],
> +			.data = &vhci,
>  			.size_data = sizeof(void *),
>  		};
diff mbox series

Patch

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index f845b91848b9..dfbdc77108e5 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -1139,8 +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);
 		vhci->vhci_hcd_hs->vhci = vhci;
@@ -1257,7 +1256,7 @@  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 +1270,7 @@  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 +1337,7 @@  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 +1395,7 @@  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 +1430,7 @@  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);
 
@@ -1506,6 +1505,7 @@  static void del_platform_devices(void)
 static int __init vhci_hcd_init(void)
 {
 	int i, ret;
+	void *vhci;
 
 	if (usb_disabled())
 		return -ENODEV;
@@ -1522,10 +1522,11 @@  static int __init vhci_hcd_init(void)
 		goto err_driver_register;
 
 	for (i = 0; i < vhci_num_controllers; i++) {
+		vhci = &vhcis[i];
 		struct platform_device_info pdevinfo = {
 			.name = driver_name,
 			.id = i,
-			.data = &vhcis[i],
+			.data = &vhci,
 			.size_data = sizeof(void *),
 		};