From: Yu Chen <chenyu56@xxxxxxxxxx> Unable to handle kernel paging request at virtual address dead000000000108 pgd = fffffff7a3179000 [dead000000000108] *pgd=00000000230e0003, *pud=00000000230e0003, *pmd=0000000000000000 Internal error: Oops: 96000044 [#1] PREEMPT SMP Modules linked in: CPU: 2 PID: 1 Comm: init Tainted: G W 4.4.23+ #1 TGID: 1 Comm: init Hardware name: kirin970 (DT) task: fffffff99f190000 ti: fffffff99f1740e0 task.ti: fffffff99f1740e0 PC is at dwc3_gadget_giveback+0xa8/0x228 LR is at dwc3_remove_requests+0x44/0x88 The crash occurred when usb work as rndis device and __dwc3_gadget_kick_transfer return error in __dwc3_gadget_ep_queue. The request submited in __dwc3_gadget_ep_queue is moved to started_list but not kicked. It is stil on started_list although __dwc3_gadget_kick_transfer failed. When dwc3_gadget_ep_queue return error to u_ether driver, the request will be resubmit to dwc3 driver. At last, the same request is both on started_list and pending_list, it will be list_del twice in dwc3_remove_requests and cause crash. Signed-off-by: Yu Chen <chenyu56@xxxxxxxxxx> --- drivers/usb/dwc3/gadget.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 639dd1b163a0..a913e64ca4e0 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1278,9 +1278,28 @@ static void dwc3_gadget_start_isoc(struct dwc3 *dwc, __dwc3_gadget_start_isoc(dwc, dep, cur_uf); } +static int dwc3_gadget_is_req_pengding_or_started(struct dwc3_ep *dep, + struct dwc3_request *req) +{ + struct dwc3_request *iterate_req; + + list_for_each_entry(iterate_req, &dep->pending_list, list) { + if (iterate_req == req) + return 1; + } + + list_for_each_entry(iterate_req, &dep->started_list, list) { + if (iterate_req == req) + return 1; + } + + return 0; +} + static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) { struct dwc3 *dwc = dep->dwc; + int ret; if (!dep->endpoint.desc) { dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n", @@ -1334,7 +1353,14 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) } out: - return __dwc3_gadget_kick_transfer(dep); + ret = __dwc3_gadget_kick_transfer(dep); + if (ret && dwc3_gadget_is_req_pengding_or_started(dep, req)) { + dev_dbg(dwc->dev, "%s: req still on list, return 0\n", + dep->name); + ret = 0; + } + + return ret; } static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request, -- 2.15.0-rc2 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html