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Re: panic: UBSan: Undefined Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/netinet6/scope6.c:LINE, member access w

On 20.09.2019 16:43, Joerg Sonnenberger wrote:
> On Fri, Sep 20, 2019 at 02:58:31PM +0200, Kamil Rytarowski wrote:
>> memcpy/memcmp is too invasive here as we need to change macros shared
>> with userland.
> The kernel use falls into two categories:
> (1) strict alignment architectures are supposed to have ensured the
> alignment of all packet data via appropiate pulldowns.
> (2) non-strict alignment architectures assume that access is fine.
> Given that this is performance sensitive, doing unnecessary work here
> really matters. So when fuzzing with ubsan, enable the strict alignment
> logic...
> Joerg

OK, so I presume that the way to go is to disable __NO_STRICT_ALIGNMENT
under UBSan and this will force IP6_HDR_ALIGNED_P() to be used with
alignment requirements.

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