Re: [PATCH 1/2] hw/usb/hcd-ohci: Fix #1510, #303: pid not IN or OUT

[Cord Amfmgm <dmamfmgm@gmail.com>]

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On Mon, May 20, 2024 at 11:55 AM Peter Maydell <peter.maydell@linaro.org>
wrote:

> On Thu, 9 May 2024 at 01:30, David Hubbard <dmamfmgm@gmail.com> wrote:
> >
> > From: Cord Amfmgm <dmamfmgm@gmail.com>
> >
> > This changes the ohci validation to not assert if invalid data is fed to
> the
> > ohci controller. The poc in https://bugs.launchpad.net/qemu/+bug/1907042
> and
> > migrated to bug #303 does the following to feed it a SETUP pid (valid)
> > at an EndPt of 1 (invalid - all SETUP pids must be addressed to EndPt 0):
> >
> >         uint32_t MaxPacket = 64;
> >         uint32_t TDFormat = 0;
> >         uint32_t Skip = 0;
> >         uint32_t Speed = 0;
> >         uint32_t Direction = 0;  /* #define OHCI_TD_DIR_SETUP 0 */
> >         uint32_t EndPt = 1;
> >         uint32_t FuncAddress = 0;
> >         ed->attr = (MaxPacket << 16) | (TDFormat << 15) | (Skip << 14)
> >                    | (Speed << 13) | (Direction << 11) | (EndPt << 7)
> >                    | FuncAddress;
> >         ed->tailp = /*TDQTailPntr= */ 0;
> >         ed->headp = ((/*TDQHeadPntr= */ &td[0]) & 0xfffffff0)
> >                    | (/* ToggleCarry= */ 0 << 1);
> >         ed->next_ed = (/* NextED= */ 0 & 0xfffffff0)
> >
> > qemu-fuzz also caught the same issue in #1510. They are both fixed by
> this
> > patch.
> >
> > With a tiny OS[1] that boots and executes the poc the repro shows the
> issue:
> >
> > * OS that sends USB requests to a USB mass storage device
> >   but sends a SETUP with EndPt = 1
> > * qemu 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6.19)
> > * qemu HEAD (4e66a0854)
> > * Actual OHCI controller (hardware)
> >
> > Command line:
> > qemu-system-x86_64 -m 20 \
> >  -device pci-ohci,id=ohci \
> >  -drive if=none,format=raw,id=d,file=testmbr.raw \
> >  -device usb-storage,bus=ohci.0,drive=d \
> >  --trace "usb_*" --trace "ohci_*" -D qemu.log
> >
> > Results are:
> >
> >  qemu 6.2.0 | qemu HEAD | actual HW
> > ------------+-----------+----------------
> >  assertion  | assertion | sets stall bit
> >
> > The assertion message is:
> >
> > > qemu-system-x86_64: ../../hw/usb/core.c:744: usb_ep_get: Assertion
> `pid == USB_TOKEN_IN || pid == USB_TOKEN_OUT' failed.
> > > Aborted (core dumped)
> >
> > Tip: if the flags "-serial pty -serial stdio" are added to the command
> line
> > the poc outputs its USB requests like this:
> >
> > > Free mem 2M ohci port0 conn FS
> > > setup { 80 6 0 1 0 0 8 0 }
> > > ED info=80000 { mps=8 en=0 d=0 } tail=c20920
> > >   td0 c20880 nxt=c20960 f2000000 setup cbp=c20900 be=c20907
>  cbp=0 be=c20907
> > >   td1 c20960 nxt=c20980 f3140000    in cbp=c20908 be=c2090f
>  cbp=0 be=c2090f
> > >   td2 c20980 nxt=c20920 f3080000   out cbp=0 be=0
>  cbp=0 be=0
> > >    rx { 12 1 0 2 0 0 0 8 }
> > > setup { 0 5 1 0 0 0 0 0 } tx {}
> > > ED info=80000 { mps=8 en=0 d=0 } tail=c20880
> > >   td0 c20920 nxt=c20960 f2000000 setup cbp=c20900 be=c20907
>  cbp=0 be=c20907
> > >   td1 c20960 nxt=c20880 f3100000    in cbp=0 be=0
>  cbp=0 be=0
> > > setup { 80 6 0 1 0 0 12 0 }
> > > ED info=80081 { mps=8 en=0 d=1 } tail=c20960
> > >   td0 c20880 nxt=c209c0 f2000000 setup cbp=c20920 be=c20927
> > >   td1 c209c0 nxt=c209e0 f3140000    in cbp=c20928 be=c20939
> > >   td2 c209e0 nxt=c20960 f3080000   out cbp=0 be=0qemu-system-x86_64:
> ../../hw/usb/core.c:744: usb_ep_get: Assertion `pid == USB_TOKEN_IN || pid
> == USB_TOKEN_OUT' failed.
> > > Aborted (core dumped)
> >
> > [1] The OS disk image has been emailed to philmd@linaro.org,
> mjt@tls.msk.ru,
> > and kraxel@redhat.com:
> >
> > * testBadSetup.img.xz
> > * sha256:
> 045b43f4396de02b149518358bf8025d5ba11091e86458875339fc649e6e5ac6
> >
> > Signed-off-by: Cord Amfmgm <dmamfmgm@gmail.com>
> > ---
> >  hw/usb/hcd-ohci.c   | 5 +++++
> >  hw/usb/trace-events | 1 +
> >  2 files changed, 6 insertions(+)
> >
> > diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
> > index fc8fc91a1d..acd6016980 100644
> > --- a/hw/usb/hcd-ohci.c
> > +++ b/hw/usb/hcd-ohci.c
> > @@ -927,6 +927,11 @@ static int ohci_service_td(OHCIState *ohci, struct
> ohci_ed *ed)
> >      case OHCI_TD_DIR_SETUP:
> >          str = "setup";
> >          pid = USB_TOKEN_SETUP;
> > +        if (OHCI_BM(ed->flags, ED_EN) > 0) {  /* setup only allowed to
> ep 0 */
> > +            trace_usb_ohci_td_bad_pid(str, ed->flags, td.flags);
> > +            ohci_die(ohci);
> > +            return 1;
> > +        }
> >          break;
> >      default:
> >          trace_usb_ohci_td_bad_direction(dir);
> > diff --git a/hw/usb/trace-events b/hw/usb/trace-events
> > index ed7dc210d3..fd7b90d70c 100644
> > --- a/hw/usb/trace-events
> > +++ b/hw/usb/trace-events
> > @@ -28,6 +28,7 @@ usb_ohci_iso_td_data_overrun(int ret, ssize_t len)
> "DataOverrun %d > %zu"
> >  usb_ohci_iso_td_data_underrun(int ret) "DataUnderrun %d"
> >  usb_ohci_iso_td_nak(int ret) "got NAK/STALL %d"
> >  usb_ohci_iso_td_bad_response(int ret) "Bad device response %d"
> > +usb_ohci_td_bad_pid(const char *s, uint32_t edf, uint32_t tdf) "Bad pid
> %s: ed.flags 0x%x td.flags 0x%x"
> >  usb_ohci_port_attach(int index) "port #%d"
> >  usb_ohci_port_detach(int index) "port #%d"
> >  usb_ohci_port_wakeup(int index) "port #%d"
> > --
>
> For this patch,
>
> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
>
> Are you happy for me to take this patch and apply it to
> target-arm.next with the git Author and Signed-off-by:
> lines both being "David Hubbard" ? (I think if I understand
> our conversation in the other mail thread that that's the
> right thing.)
>
> thanks
> -- PMM
>

For this patch (the SETUP pid validation), I am happy if you take the patch
and apply it with Author and Signed-off-by set to "David Hubbard." Please
go ahead.

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