Re: [PATCH] net: tulip: Restrict DMA engine to memories

[Jason Wang]

在 2022/8/24 10:26, Jason Wang 写道:
> On Sun, Aug 21, 2022 at 8:29 PM Zheyu Ma <zheyuma97@gmail.com> wrote:
> > The DMA engine is started by I/O access and then itself accesses the
> > I/O registers, triggering a reentrancy bug.
> >
> > The following log can reveal it:
> > ==5637==ERROR: AddressSanitizer: stack-overflow
> >      #0 0x5595435f6078 in tulip_xmit_list_update qemu/hw/net/tulip.c:673
> >      #1 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
> >      #2 0x559544637f86 in memory_region_write_accessor 
> > qemu/softmmu/memory.c:492:5
> >      #3 0x5595446379fa in access_with_adjusted_size qemu/softmmu/memory.c:554:18
> >      #4 0x5595446372fa in memory_region_dispatch_write qemu/softmmu/memory.c
> >      #5 0x55954468b74c in flatview_write_continue qemu/softmmu/physmem.c:2825:23
> >      #6 0x559544683662 in flatview_write qemu/softmmu/physmem.c:2867:12
> >      #7 0x5595446833f3 in address_space_write qemu/softmmu/physmem.c:2963:18
> >      #8 0x5595435fb082 in dma_memory_rw_relaxed 
> > /home/mzy/truman/third_party/qemu/include/sysemu/dma.h:87:12
> >      #9 0x5595435fb082 in dma_memory_rw 
> > /home/mzy/truman/third_party/qemu/include/sysemu/dma.h:130:12
> >      #10 0x5595435fb082 in dma_memory_write 
> > /home/mzy/truman/third_party/qemu/include/sysemu/dma.h:171:12
> >      #11 0x5595435fb082 in stl_le_dma 
> > /home/mzy/truman/third_party/qemu/include/sysemu/dma.h:272:1
> >      #12 0x5595435fb082 in stl_le_pci_dma 
> > /home/mzy/truman/third_party/qemu/include/hw/pci/pci.h:910:1
> >      #13 0x5595435fb082 in tulip_desc_write qemu/hw/net/tulip.c:101:9
> >      #14 0x5595435f7e3d in tulip_xmit_list_update qemu/hw/net/tulip.c:706:9
> >      #15 0x5595435f204a in tulip_write qemu/hw/net/tulip.c:805:13
> >
> > Fix this bug by restricting the DMA engine to memories regions.
> >
> > Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
> Queued for 7.2.


Ok, I saw v2, so I've queued that version since it has a better change log.

Thanks


> Thanks
>
> > ---
> >   hw/net/tulip.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/hw/net/tulip.c b/hw/net/tulip.c
> > index 097e905bec..b9e42c322a 100644
> > --- a/hw/net/tulip.c
> > +++ b/hw/net/tulip.c
> > @@ -70,7 +70,7 @@ static const VMStateDescription vmstate_pci_tulip = {
> >   static void tulip_desc_read(TULIPState *s, hwaddr p,
> >           struct tulip_descriptor *desc)
> >   {
> > -    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
> > +    const MemTxAttrs attrs = { .memory = true };
> >
> >       if (s->csr[0] & CSR0_DBO) {
> >           ldl_be_pci_dma(&s->dev, p, &desc->status, attrs);
> > @@ -88,7 +88,7 @@ static void tulip_desc_read(TULIPState *s, hwaddr p,
> >   static void tulip_desc_write(TULIPState *s, hwaddr p,
> >           struct tulip_descriptor *desc)
> >   {
> > -    const MemTxAttrs attrs = MEMTXATTRS_UNSPECIFIED;
> > +    const MemTxAttrs attrs = { .memory = true };
> >
> >       if (s->csr[0] & CSR0_DBO) {
> >           stl_be_pci_dma(&s->dev, p, desc->status, attrs);
> > --
> > 2.25.1