| Message ID | 1644836933-141376-3-git-send-email-dh10.jung@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fix ep command fail issue in dequeue | expand |
On Mon, Feb 14, 2022 at 08:08:53PM +0900, Daehwan Jung wrote: > We added cleanup cancelled requests when ep cmd timeout on ep dequeue > because there's no complete interrupt then. But, we find out new case > that complete interrupt comes up later. list_for_each_entry_safe is > used when cleanup cancelled requests and it has vulnerabilty on multi-core > environment. dwc3_gadget_giveback unlocks dwc->lock temporarily and other > core(ISR) can get lock and try to cleanup them again. It could cause > list_del corruption and we use DWC3_EP_END_TRANSFER_PENDING to prevent it. > > 1. MTP server cancels -> ep dequeue -> ep cmd timeout(END_TRANSFER) > -> cleanup cancelled requests -> dwc3_gadget_giveback -> > list_del -> release lock temporarily > 2. Complete with END_TRANSFER -> ISR(dwc3_gadget_endpoint_command_complete) > gets lock -> cleanup cancelled requests -> dwc3_gadget_giveback > -> list_del > 3. MTP server process gets lock again > -> tries to access POISON list(list_del corruption) > > [2: MtpServer: 5032] dwc3 10b00000.dwc3: request cancelled > with wrong reason:5 > [2: MtpServer: 5032] list_del corruption, > ffffff88b6963968->next is LIST_POISON1 (dead000000000100) > > Signed-off-by: Daehwan Jung <dh10.jung@samsung.com> > --- > drivers/usb/dwc3/gadget.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) What commit id does this fix? thanks, greg k-h
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 3ad3bc5813ca..bac3814894e2 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2046,8 +2046,11 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, /* If ep cmd fails, then force to giveback cancelled requests here */ if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING)) { - dep->flags &= ~DWC3_EP_TRANSFER_STARTED; + dep->flags |= DWC3_EP_END_TRANSFER_PENDING; dwc3_gadget_ep_cleanup_cancelled_requests(dep); + + dep->flags &= ~DWC3_EP_TRANSFER_STARTED; + dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING; } dep->flags &= ~DWC3_EP_WAIT_TRANSFER_COMPLETE; @@ -3426,9 +3429,11 @@ static void dwc3_gadget_endpoint_command_complete(struct dwc3_ep *dep, if (dep->stream_capable) dep->flags |= DWC3_EP_IGNORE_NEXT_NOSTREAM; + if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING)) + dwc3_gadget_ep_cleanup_cancelled_requests(dep); + dep->flags &= ~DWC3_EP_END_TRANSFER_PENDING; dep->flags &= ~DWC3_EP_TRANSFER_STARTED; - dwc3_gadget_ep_cleanup_cancelled_requests(dep); if (dep->flags & DWC3_EP_PENDING_CLEAR_STALL) { struct dwc3 *dwc = dep->dwc;
We added cleanup cancelled requests when ep cmd timeout on ep dequeue because there's no complete interrupt then. But, we find out new case that complete interrupt comes up later. list_for_each_entry_safe is used when cleanup cancelled requests and it has vulnerabilty on multi-core environment. dwc3_gadget_giveback unlocks dwc->lock temporarily and other core(ISR) can get lock and try to cleanup them again. It could cause list_del corruption and we use DWC3_EP_END_TRANSFER_PENDING to prevent it. 1. MTP server cancels -> ep dequeue -> ep cmd timeout(END_TRANSFER) -> cleanup cancelled requests -> dwc3_gadget_giveback -> list_del -> release lock temporarily 2. Complete with END_TRANSFER -> ISR(dwc3_gadget_endpoint_command_complete) gets lock -> cleanup cancelled requests -> dwc3_gadget_giveback -> list_del 3. MTP server process gets lock again -> tries to access POISON list(list_del corruption) [2: MtpServer: 5032] dwc3 10b00000.dwc3: request cancelled with wrong reason:5 [2: MtpServer: 5032] list_del corruption, ffffff88b6963968->next is LIST_POISON1 (dead000000000100) Signed-off-by: Daehwan Jung <dh10.jung@samsung.com> --- drivers/usb/dwc3/gadget.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)