Re: [PATCH v1 2/2] usb: dwc3: Prevent cleanup cancelled requests at the same time.

[Greg Kroah-Hartman]

On Mon, Feb 14, 2022 at 06:37:18PM +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)
> 
> [  205.014697] [2:      MtpServer: 5032] dwc3 10b00000.dwc3: request cancelled with wrong reason:5
> [  205.014719] [2:      MtpServer: 5032] list_del corruption, ffffff88b6963968->next is LIST_POISON1 (dead000000000100)
> 
> Change-Id: I9df055c6c04855edd09e330300914454a6657a23
> Signed-off-by: Daehwan Jung <dh10.jung@xxxxxxxxxxx>
> 
> Change-Id: If87c88c3bb4c17ea1a5bde2bfec1382769f7ecab
> Signed-off-by: Daehwan Jung <dh10.jung@xxxxxxxxxxx>

Why did you sign off on this twice?

And did you run it through checkpatch.pl?  It would have reminded you
that Change-Id: should not be on patches :(

Same for patch 1/1.

Please fix.

thanks,

greg k-h