Description
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Replace list_for_each_entry_safe() if using giveback The list_for_each_entry_safe() macro saves the current item (n) and the item after (n+1), so that n can be safely removed without corrupting the list. However, when traversing the list and removing items using gadget giveback, the DWC3 lock is briefly released, allowing other routines to execute. There is a situation where, while items are being removed from the cancelled_list using dwc3_gadget_ep_cleanup_cancelled_requests(), the pullup disable routine is running in parallel (due to UDC unbind). As the cleanup routine removes n, and the pullup disable removes n+1, once the cleanup retakes the DWC3 lock, it references a request who was already removed/handled. With list debug enabled, this leads to a panic. Ensure all instances of the macro are replaced where gadget giveback is used. Example call stack: Thread#1: __dwc3_gadget_ep_set_halt() - CLEAR HALT -> dwc3_gadget_ep_cleanup_cancelled_requests() ->list_for_each_entry_safe() ->dwc3_gadget_giveback(n) ->dwc3_gadget_del_and_unmap_request()- n deleted[cancelled_list] ->spin_unlock ->Thread#2 executes ... ->dwc3_gadget_giveback(n+1) ->Already removed! Thread#2: dwc3_gadget_pullup() ->waiting for dwc3 spin_lock ... ->Thread#1 released lock ->dwc3_stop_active_transfers() ->dwc3_remove_requests() ->fetches n+1 item from cancelled_list (n removed by Thread#1) ->dwc3_gadget_giveback() ->dwc3_gadget_del_and_unmap_request()- n+1 deleted[cancelled_list] ->spin_unlock
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
d4f1afe5e896c18ae01099a85dab5e1a198bd2a8 to < 1c6e5dc3b639c96e6839a8d1b8e951923fdfd34aaffectedd4f1afe5e896c18ae01099a85dab5e1a198bd2a8 to < 2424307cdf421ac72075a1384eae4e4199ab6457affectedd4f1afe5e896c18ae01099a85dab5e1a198bd2a8 to < 26a7e6832afe9d9a991cfd9015177f083cf959ccaffectedd4f1afe5e896c18ae01099a85dab5e1a198bd2a8 to < bf594d1d0c1d7b895954018043536ffd327844f9affectedd7ff2e3ff0e09d57b43014fe26b13bb3c9677254affected4.19.57 to < 4.20affected
Linux Linux
Default version status: affected
5.0affected0 to < 5.0unaffected5.15.47 to ≤ 5.15.*unaffected5.17.15 to ≤ 5.17.*unaffected5.18.4 to ≤ 5.18.*unaffected5.19 to ≤ *unaffected