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

[Jason Wang <jasowang@redhat.com>]

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


>