Re: [PATCH] hw/net: Discard overly fragmented packets

[Thomas Huth <thuth@redhat.com>]

On 11/08/2021 06.08, Jason Wang wrote:
> 
> 在 2021/8/4 上午9:43, Jason Wang 写道:
>>
>> 在 2021/8/3 下午5:51, Philippe Mathieu-Daudé 写道:
>>> On 8/3/21 11:33 AM, Thomas Huth wrote:
>>>> On 05/07/2021 10.40, Philippe Mathieu-Daudé wrote:
>>>>> Our infrastructure can handle fragmented packets up to
>>>>> NET_MAX_FRAG_SG_LIST (64) pieces. This hard limit has
>>>>> been proven enough in production for years. If it is
>>>>> reached, it is likely an evil crafted packet. Discard it.
>>>>>
>>>>> Include the qtest reproducer provided by Alexander Bulekov:
>>>>>
>>>>>     $ make check-qtest-i386
>>>>>     ...
>>>>>     Running test qtest-i386/fuzz-vmxnet3-test
>>>>>     qemu-system-i386: net/eth.c:334: void
>>>>> eth_setup_ip4_fragmentation(const void *, size_t, void *, size_t,
>>>>> size_t, size_t, _Bool):
>>>>>     Assertion `frag_offset % IP_FRAG_UNIT_SIZE == 0' failed.
>>>>>
>>>>> Cc: qemu-stable@nongnu.org
>>>>> Reported-by: OSS-Fuzz (Issue 35799)
>>>>> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/460
>>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>>>>> ---
>>>>>    hw/net/net_tx_pkt.c             |   8 ++
>>>>>    tests/qtest/fuzz-vmxnet3-test.c | 195 ++++++++++++++++++++++++++++++++
>>>>>    MAINTAINERS                     |   1 +
>>>>>    tests/qtest/meson.build         |   1 +
>>>>>    4 files changed, 205 insertions(+)
>>>>>    create mode 100644 tests/qtest/fuzz-vmxnet3-test.c
>>>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>>>>
>>>> Jason, I think this would even still qualify for QEMU v6.1 ?
>>> Yes, easy one for 6.1.
>>
>>
>> Yes, this will be included for rc3.
>>
>> Thanks
> 
> For some reasons it misses rc3.
> 
> I will include it for 6.2.
> 
> Sorry.

  Hi Jason,

looks like this fell through the cracks again ... could you maybe pick it up 
now for QEMU 7.1 ?

  Thomas