diff options
| author | Albert Wang <albertccwang@google.com> | 2022-05-18 14:13:15 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-05-19 18:15:03 +0200 |
| commit | 3c5880745b4439ac64eccdb040e37fc1cc4c5406 (patch) | |
| tree | 24b0ef1bdf16df383cf13d0639a601b193524200 /drivers/usb | |
| parent | 6c5ba7395b1badce5e0b8e597907751e952646cb (diff) | |
usb: dwc3: gadget: Move null pinter check to proper place
When dwc3_gadget_ep_cleanup_completed_requests() called to
dwc3_gadget_giveback() where the dwc3 lock is released, other thread is
able to execute. In this situation, usb_ep_disable() gets the chance to
clear endpoint descriptor pointer which leds to the null pointer
dereference problem. So needs to move the null pointer check to a proper
place.
Example call stack:
Thread#1:
dwc3_thread_interrupt()
spin_lock
-> dwc3_process_event_buf()
-> dwc3_process_event_entry()
-> dwc3_endpoint_interrupt()
-> dwc3_gadget_endpoint_trbs_complete()
-> dwc3_gadget_ep_cleanup_completed_requests()
...
-> dwc3_giveback()
spin_unlock
Thread#2 executes
Thread#2:
configfs_composite_disconnect()
-> __composite_disconnect()
-> ffs_func_disable()
-> ffs_func_set_alt()
-> ffs_func_eps_disable()
-> usb_ep_disable()
wait for dwc3 spin_lock
Thread#1 released lock
clear endpoint.desc
Fixes: 26288448120b ("usb: dwc3: gadget: Fix null pointer exception")
Cc: stable <stable@kernel.org>
Signed-off-by: Albert Wang <albertccwang@google.com>
Link: https://lore.kernel.org/r/20220518061315.3359198-1-albertccwang@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/dwc3/gadget.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 8c366fa82105..00427d108ab9 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3384,14 +3384,14 @@ static bool dwc3_gadget_endpoint_trbs_complete(struct dwc3_ep *dep, struct dwc3 *dwc = dep->dwc; bool no_started_trb = true; - if (!dep->endpoint.desc) - return no_started_trb; - dwc3_gadget_ep_cleanup_completed_requests(dep, event, status); if (dep->flags & DWC3_EP_END_TRANSFER_PENDING) goto out; + if (!dep->endpoint.desc) + return no_started_trb; + if (usb_endpoint_xfer_isoc(dep->endpoint.desc) && list_empty(&dep->started_list) && (list_empty(&dep->pending_list) || status == -EXDEV)) |