| From 0d5281406c3e50bc3b5fb07678417f0c942004c2 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 5 May 2022 12:46:18 +0200 |
| Subject: usb: dwc2: gadget: don't reset gadget's driver->bus |
| |
| From: Marek Szyprowski <m.szyprowski@samsung.com> |
| |
| [ Upstream commit 3120aac6d0ecd9accf56894aeac0e265f74d3d5a ] |
| |
| UDC driver should not touch gadget's driver internals, especially it |
| should not reset driver->bus. This wasn't harmful so far, but since |
| commit fc274c1e9973 ("USB: gadget: Add a new bus for gadgets") gadget |
| subsystem got it's own bus and messing with ->bus triggers the |
| following NULL pointer dereference: |
| |
| dwc2 12480000.hsotg: bound driver g_ether |
| 8<--- cut here --- |
| Unable to handle kernel NULL pointer dereference at virtual address 00000000 |
| [00000000] *pgd=00000000 |
| Internal error: Oops: 5 [#1] SMP ARM |
| Modules linked in: ... |
| CPU: 0 PID: 620 Comm: modprobe Not tainted 5.18.0-rc5-next-20220504 #11862 |
| Hardware name: Samsung Exynos (Flattened Device Tree) |
| PC is at module_add_driver+0x44/0xe8 |
| LR is at sysfs_do_create_link_sd+0x84/0xe0 |
| ... |
| Process modprobe (pid: 620, stack limit = 0x(ptrval)) |
| ... |
| module_add_driver from bus_add_driver+0xf4/0x1e4 |
| bus_add_driver from driver_register+0x78/0x10c |
| driver_register from usb_gadget_register_driver_owner+0x40/0xb4 |
| usb_gadget_register_driver_owner from do_one_initcall+0x44/0x1e0 |
| do_one_initcall from do_init_module+0x44/0x1c8 |
| do_init_module from load_module+0x19b8/0x1b9c |
| load_module from sys_finit_module+0xdc/0xfc |
| sys_finit_module from ret_fast_syscall+0x0/0x54 |
| Exception stack(0xf1771fa8 to 0xf1771ff0) |
| ... |
| dwc2 12480000.hsotg: new device is high-speed |
| ---[ end trace 0000000000000000 ]--- |
| |
| Fix this by removing driver->bus entry reset. |
| |
| Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> |
| Link: https://lore.kernel.org/r/20220505104618.22729-1-m.szyprowski@samsung.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/usb/dwc2/gadget.c | 1 - |
| 1 file changed, 1 deletion(-) |
| |
| diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c |
| index 65bcbbad6d54..44bab6727b43 100644 |
| --- a/drivers/usb/dwc2/gadget.c |
| +++ b/drivers/usb/dwc2/gadget.c |
| @@ -3445,7 +3445,6 @@ static int dwc2_hsotg_udc_start(struct usb_gadget *gadget, |
| |
| WARN_ON(hsotg->driver); |
| |
| - driver->driver.bus = NULL; |
| hsotg->driver = driver; |
| hsotg->gadget.dev.of_node = hsotg->dev->of_node; |
| hsotg->gadget.speed = USB_SPEED_UNKNOWN; |
| -- |
| 2.35.1 |
| |