UPSTREAM: usb: gadget: udc: renesas_usb3: Fix use after free bug in renesas_usb3_remove due to race condition
[ Upstream commit 2b947f8769be8b8181dc795fd292d3e7120f5204 ]
In renesas_usb3_probe, role_work is bound with renesas_usb3_role_work.
renesas_usb3_start will be called to start the work.
If we remove the driver which will call usbhs_remove, there may be
an unfinished work. The possible sequence is as follows:
CPU0 CPU1
renesas_usb3_role_work
renesas_usb3_remove
usb_role_switch_unregister
device_unregister
kfree(sw)
//free usb3->role_sw
usb_role_switch_set_role
//use usb3->role_sw
The usb3->role_sw could be freed under such circumstance and then
used in usb_role_switch_set_role.
This bug was found by static analysis. And note that removing a
driver is a root-only operation, and should never happen in normal
case. But the root user may directly remove the device which
will also trigger the remove function.
Fix it by canceling the work before cleanup in the renesas_usb3_remove.
Bug: 289003615
Fixes: 39facfa01c9f ("usb: gadget: udc: renesas_usb3: Add register of usb role switch")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20230320062931.505170-1-zyytlz.wz@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit df2380520926bdbc264cffab0f45da9a21f304c8)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I79a1dbeba9a90ee5daf94648ef6a32207b283561
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c
index 0bbd180..e04acf2 100644
--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -2553,6 +2553,7 @@
debugfs_remove_recursive(usb3->dentry);
device_remove_file(&pdev->dev, &dev_attr_role);
+ cancel_work_sync(&usb3->role_work);
usb_role_switch_unregister(usb3->role_sw);
usb_del_gadget_udc(&usb3->gadget);
