Jason Wang 于2020年3月27日周五 上午10:53写道： > > On 2020/3/27 上午10:35, Li Qiang wrote: > > > > > > Jason Wang > > > 于2020年3月27日周五 上午10:09写道： > > > > > > On 2020/3/24 下午10:54, Li Qiang wrote: > > > > > > > > > Jason Wang > > >> > > > 于2020年3月24日周二 下午1:45写道： > > > > > > > > > On 2020/3/24 上午9:29, Li Qiang wrote: > > > > > > > > > > > > P J P > > > > > > > > >>> > > > 于2020年3月23日周一 > > > > 下午8:24写道： > > > > > > > > From: Prasad J Pandit > > > > > > > > > > > >>> > > > > > > > > Tulip network driver while copying tx/rx buffers does > > not check > > > > frame size against r/w data length. This may lead to > > OOB buffer > > > > access. Add check to avoid it. > > > > > > > > Limit iterations over descriptors to avoid potential > > infinite > > > > loop issue in tulip_xmit_list_update. > > > > > > > > Reported-by: Li Qiang > > > > > > > > > > > >>> > > > > Reported-by: Ziming Zhang > > > > > > > > > > > >>> > > > > Reported-by: Jason Wang > > > > > > > > > > > >>> > > > > Signed-off-by: Prasad J Pandit > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > Tested-by: Li Qiang > > > > > > > > >>> > > > > But I have a minor question.... > > > > > > > > --- > > > > hw/net/tulip.c | 36 +++++++++++++++++++++++++++--------- > > > > 1 file changed, 27 insertions(+), 9 deletions(-) > > > > > > > > Update v3: return a value from tulip_copy_tx_buffers() > > and avoid > > > > infinite loop > > > > -> > > > > > > https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html > > > > > > > > diff --git a/hw/net/tulip.c b/hw/net/tulip.c > > > > index cfac2719d3..fbe40095da 100644 > > > > --- a/hw/net/tulip.c > > > > +++ b/hw/net/tulip.c > > > > @@ -170,6 +170,10 @@ static void > > tulip_copy_rx_bytes(TULIPState > > > > *s, struct tulip_descriptor *desc) > > > > } else { > > > > len = s->rx_frame_len; > > > > } > > > > + > > > > + if (s->rx_frame_len + len >= > > sizeof(s->rx_frame)) { > > > > + return; > > > > + } > > > > > > > > > > > > > > > > Why here is '>=' instead of '>'. > > > > IIUC the total sending length can reach to > > sizeof(s->rx_frame). > > > > Same in the other place in this patch. > > > > > > > > > Yes, this need to be fixed. > > > > > > > > > > > > > > PS: I have planned to write a qtest case. But my personal > > qemu dev > > > > environment is broken. > > > > I will try to write it tonight or tomorrow night. > > > > > > > > > Cool, good to know this. > > > > > > > > > Hi all, > > > I have countered an interesting issue. Let's look at the > > definition of > > > TULIPState. > > > > > > 21 typedef struct TULIPState { > > > 22 PCIDevice dev; > > > 23 MemoryRegion io; > > > 24 MemoryRegion memory; > > > 25 NICConf c; > > > 26 qemu_irq irq; > > > 27 NICState *nic; > > > 28 eeprom_t *eeprom; > > > 29 uint32_t csr[16]; > > > 30 > > > 31 /* state for MII */ > > > 32 uint32_t old_csr9; > > > 33 uint32_t mii_word; > > > 34 uint32_t mii_bitcnt; > > > 35 > > > 36 hwaddr current_rx_desc; > > > 37 hwaddr current_tx_desc; > > > 38 > > > 39 uint8_t rx_frame[2048]; > > > 40 uint8_t tx_frame[2048]; > > > 41 uint16_t tx_frame_len; > > > 42 uint16_t rx_frame_len; > > > 43 uint16_t rx_frame_size; > > > 44 > > > 45 uint32_t rx_status; > > > 46 uint8_t filter[16][6]; > > > 47 } TULIPState; > > > > > > Here we can see the overflow is occured after 'tx_frame'. > > > In my quest, I have see the overflow(the s->tx_frame_len is big). > > > However here doesn't cause SEGV in qtest. > > > In real case, the qemu process will access the data after > > TULIPState > > > in heap and trigger segv. > > > However in qtest mode I don't know how to trigger this. > > > > > > If it's just the mangling of tx_frame_len, it won't hit SIGSEV. > > > > I wonder maybe, somehow that large tx_frame_len is used for buffer > > copying or other stuffs that can lead the crash. > > > > > > This is because in real qemu process, the OOB copy corrupts the head > > data after 'TULIPState' struct. > > And maybe later(other thread) access the corrupted data thus leading > > crash. > > > Ok, so I think ASAN can detect this crash. But I'm not sure whether or > not it was enabled for qtest. If not, we probably need that. > > Yes, I think this is the solution. > I wrote a qtest for virtio-net that can lead OOB, so it should probably > work for tulip but need to check. > > Or if you don't want to depend on ASAN, we can check user visible status > after tx_frame[], but it looks to me all other fields are not visible by > guest. > > Right, I have spent a lot of time to find a guest visible status but not find it. > Maybe we can reorder to place csr[] after tx_frame[] then check csr[] > afterwards. > > I think it's not worth to change this just for a test case. I will test the ASAN solution asap. Thanks, Li Qiang > > > However in qtest mode, I don't remember the core code of qtest. But > > seems it's not a really VM? just a interface emulation. > > > If my memory is correct, it's not a VM. > > Thanks > > > > In my case, it's backtrace is as this: > > Program received signal SIGSEGV, Segmentation fault. > > [Switching to Thread 0x7ffbdb7fe700 (LWP 60813)] > > 0x0000000000000000 in ?? () > > ... > > (gdb) bt > > #0 0x0000000000000000 in () > > #1 0x0000555555a7dfa3 in qemu_set_irq (irq=0x5555579e0710, level=1) > > at hw/core/irq.c:44 > > #2 0x0000555555b2b87a in tulip_update_int (s=0x5555579da7c0) at > > hw/net/tulip.c:121 > > #3 0x0000555555b2cdd9 in tulip_xmit_list_update (s=0x5555579da7c0) at > > hw/net/tulip.c:667 > > #4 0x0000555555b2d19d in tulip_write (opaque=0x5555579da7c0, addr=32, > > data=931909632, size=4) at hw/net/tulip.c:759 > > #5 0x000055555587eed1 in memory_region_write_accessor > > (mr=0x5555579db0b0, addr=32, value=0x7ffbdb7fd6a8, size=4, shift=0, > > mask=4294967295, attrs=...) at /xxx/qemu/memory.c:483 > > #6 0x000055555587f0da in access_with_adjusted_size (addr=32, > > value=0x7ffbdb7fd6a8, size=4, access_size_min=4, access_size_max=4, > > access_fn=0x55555587edf2 , > > mr=0x5555579db0b0, attrs=...) > > at /xxx/qemu/memory.c:544 > > #7 0x000055555588213b in memory_region_dispatch_write > > (mr=0x5555579db0b0, addr=32, data=931909632, op=MO_32, attrs=...) at > > /xxx/qemu/memory.c:1476 > > #8 0x000055555581fe9c in flatview_write_continue (fv=0x7ffbb001eae0, > > addr=49184, attrs=..., ptr=0x7ffff7e13000, len=4, addr1=32, l=4, > > mr=0x5555579db0b0) at /xxx/qemu/exec.c:3125 > > #9 0x000055555581fff4 in flatview_write (fv=0x7ffbb001eae0, > > addr=49184, attrs=..., buf=0x7ffff7e13000, len=4) at > /xxx/qemu/exec.c:3165 > > #10 0x0000555555820368 in address_space_write (as=0x555556762560 > > , addr=49184, attrs=..., buf=0x7ffff7e13000, len=4) > > at /xxx/qemu/exec.c:3256 > > #11 0x00005555558203da in address_space_rw (as=0x555556762560 > > , addr=49184, attrs=..., buf=0x7ffff7e13000, len=4, > > is_write=true) at /xxx/qemu/exec.c:3266 > > #12 0x000055555589723b in kvm_handle_io (port=49184, attrs=..., > > data=0x7ffff7e13000, direction=1, size=4, count=1) at > > /xxx/qemu/accel/kvm/kvm-all.c:2140 > > #13 0x00005555558979d6 in kvm_cpu_exec (cpu=0x555556b1e220) at > > /xxx/qemu/accel/kvm/kvm-all.c:2386 > > #14 0x00005555558701c5 in qemu_kvm_cpu_thread_fn (arg=0x555556b1e220) > > at /xxx/qemu/cpus.c:1246 > > #15 0x0000555555de3ce4 in qemu_thread_start (args=0x555556b44040) at > > util/qemu-thread-posix.c:519 > > #16 0x00007ffff5bb0e25 in start_thread () at /lib64/libpthread.so.0 > > #17 0x00007ffff58d8f1d in clone () at /lib64/libc.so.6 > > > > I will try to dig into the qtest code and hope find a way to trigger a > > segv in qtest. > > > > Thanks, > > Li Qiang > > > > > > Thanks > > > > > > > > > > The core code like this: > > > > > > qpci_device_enable(dev); > > > bar = qpci_iomap(dev, 0, NULL); > > > context_pa = guest_alloc(alloc, sizeof(context)); > > > guest_pa = guest_alloc(alloc, 4096); > > > memset(guest_data, 'A', sizeof(guest_data)); > > > context[0].status = 1 << 31; > > > context[0].control = 0x7ff << 11 | 0x7ff; > > > context[0].buf_addr2 = context_pa + sizeof(struct > tulip_descriptor); > > > context[0].buf_addr1 = guest_pa; > > > for (i = 1; i < ARRAY_SIZE(context); ++i) { > > > context_pa += sizeof(struct tulip_descriptor); > > > context[i].status = 1 << 31; > > > context[i].control = 0x7ff << 11 | 0x7ff; > > > context[i].buf_addr2 = context_pa + sizeof(struct > tulip_descriptor); > > > context[i].buf_addr1 = guest_pa; > > > } > > > > > > qtest_memwrite(dev->bus->qts, context_pa, context, > sizeof(context)); > > > qtest_memwrite(dev->bus->qts, guest_pa, guest_data, > > sizeof(guest_data)); > > > qpci_io_writel(dev, bar, 0x20, context_pa); > > > qpci_io_writel(dev, bar, 0x30, 1 << 13); > > > > > > Paolo may give some hints? > > > > > > Thanks, > > > Li Qiang > > > > > > Thanks > > > > > > > > > > > > > > Thanks, > > > > Li Qiang > > > > > > > > > > > > > > > > > > > > pci_dma_write(&s->dev, desc->buf_addr1, > > s->rx_frame + > > > > (s->rx_frame_size - s->rx_frame_len), len); > > > > s->rx_frame_len -= len; > > > > @@ -181,6 +185,10 @@ static void > > tulip_copy_rx_bytes(TULIPState > > > > *s, struct tulip_descriptor *desc) > > > > } else { > > > > len = s->rx_frame_len; > > > > } > > > > + > > > > + if (s->rx_frame_len + len >= > > sizeof(s->rx_frame)) { > > > > + return; > > > > + } > > > > pci_dma_write(&s->dev, desc->buf_addr2, > > s->rx_frame + > > > > (s->rx_frame_size - s->rx_frame_len), len); > > > > s->rx_frame_len -= len; > > > > @@ -227,7 +235,8 @@ static ssize_t > > tulip_receive(TULIPState *s, > > > > const uint8_t *buf, size_t size) > > > > > > > > trace_tulip_receive(buf, size); > > > > > > > > - if (size < 14 || size > 2048 || s->rx_frame_len || > > > > tulip_rx_stopped(s)) { > > > > + if (size < 14 || size > sizeof(s->rx_frame) - 4 > > > > + || s->rx_frame_len || tulip_rx_stopped(s)) { > > > > return 0; > > > > } > > > > > > > > @@ -275,7 +284,6 @@ static ssize_t > > > tulip_receive_nc(NetClientState > > > > *nc, > > > > return tulip_receive(qemu_get_nic_opaque(nc), > > buf, size); > > > > } > > > > > > > > - > > > > static NetClientInfo net_tulip_info = { > > > > .type = NET_CLIENT_DRIVER_NIC, > > > > .size = sizeof(NICState), > > > > @@ -558,7 +566,7 @@ static void tulip_tx(TULIPState > > *s, struct > > > > tulip_descriptor *desc) > > > > if ((s->csr[6] >> CSR6_OM_SHIFT) & > > CSR6_OM_MASK) { > > > > /* Internal or external Loopback */ > > > > tulip_receive(s, s->tx_frame, > > s->tx_frame_len); > > > > - } else { > > > > + } else if (s->tx_frame_len <= > > sizeof(s->tx_frame)) { > > > > qemu_send_packet(qemu_get_queue(s->nic), > > > > s->tx_frame, s->tx_frame_len); > > > > } > > > > @@ -570,23 +578,31 @@ static void tulip_tx(TULIPState > > *s, struct > > > > tulip_descriptor *desc) > > > > } > > > > } > > > > > > > > -static void tulip_copy_tx_buffers(TULIPState *s, struct > > > > tulip_descriptor *desc) > > > > +static int tulip_copy_tx_buffers(TULIPState *s, struct > > > > tulip_descriptor *desc) > > > > { > > > > int len1 = (desc->control >> TDES1_BUF1_SIZE_SHIFT) > & > > > > TDES1_BUF1_SIZE_MASK; > > > > int len2 = (desc->control >> TDES1_BUF2_SIZE_SHIFT) > & > > > > TDES1_BUF2_SIZE_MASK; > > > > > > > > + if (s->tx_frame_len + len1 >= sizeof(s->tx_frame)) { > > > > + return -1; > > > > + } > > > > if (len1) { > > > > pci_dma_read(&s->dev, desc->buf_addr1, > > > > s->tx_frame + s->tx_frame_len, len1); > > > > s->tx_frame_len += len1; > > > > } > > > > > > > > + if (s->tx_frame_len + len2 >= sizeof(s->tx_frame)) { > > > > + return -1; > > > > + } > > > > if (len2) { > > > > pci_dma_read(&s->dev, desc->buf_addr2, > > > > s->tx_frame + s->tx_frame_len, len2); > > > > s->tx_frame_len += len2; > > > > } > > > > desc->status = (len1 + len2) ? 0 : 0x7fffffff; > > > > + > > > > + return 0; > > > > } > > > > > > > > static void tulip_setup_filter_addr(TULIPState *s, > > uint8_t > > > *buf, > > > > int n) > > > > @@ -651,13 +667,15 @@ static uint32_t > > tulip_ts(TULIPState *s) > > > > > > > > static void tulip_xmit_list_update(TULIPState *s) > > > > { > > > > +#define TULIP_DESC_MAX 128 > > > > + uint8_t i = 0; > > > > struct tulip_descriptor desc; > > > > > > > > if (tulip_ts(s) != CSR5_TS_SUSPENDED) { > > > > return; > > > > } > > > > > > > > - for (;;) { > > > > + for (i = 0; i < TULIP_DESC_MAX; i++) { > > > > tulip_desc_read(s, s->current_tx_desc, &desc); > > > > tulip_dump_tx_descriptor(s, &desc); > > > > > > > > @@ -675,10 +693,10 @@ static void > > > > tulip_xmit_list_update(TULIPState *s) > > > > s->tx_frame_len = 0; > > > > } > > > > > > > > - tulip_copy_tx_buffers(s, &desc); > > > > - > > > > - if (desc.control & TDES1_LS) { > > > > - tulip_tx(s, &desc); > > > > + if (!tulip_copy_tx_buffers(s, &desc)) { > > > > + if (desc.control & TDES1_LS) { > > > > + tulip_tx(s, &desc); > > > > + } > > > > } > > > > } > > > > tulip_desc_write(s, s->current_tx_desc, &desc); > > > > -- > > > > 2.25.1 > > > > > > > > > > > > > > >