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    SubjectRe: KASAN: slab-out-of-bounds Read in erspan_xmit
    Thanks for the reply.

    On Tue, Jan 23, 2018 at 11:03 AM, Dmitry Vyukov <dvyukov@google.com> wrote:
    > On Tue, Jan 23, 2018 at 7:58 PM, David Ahern <dsahern@gmail.com> wrote:
    >> On 1/23/18 11:50 AM, William Tu wrote:
    >>> Hi,
    >>>
    >>> I'm new to kasan and trying to follow this instruction to reproduce the issue:
    >>> https://github.com/google/syzkaller/blob/master/docs/executing_syzkaller_programs.md
    >>>
    >>> After re-compile my kernel with KASAN related config enable, I run
    >>> $ ./syz-execprog -cover=0 -repeat=0 -procs=16 program
    >>>
    >>> I wonder does the "program" mean the repro.c.txt? or I should compile
    >>> it to binary?
    >>> # gcc -o program repro.c.txt
    >>> # ./syz-execprog myprogram
    >>> 2018/01/23 10:45:19 parsed 0 programs
    >>>
    >>> And how to use the "repro.syz.txt"?
    >>> It seems to have some command like "syz_emit_ethernet" to generate packet.
    >>> but I have no clue where to run it. Maybe I'm still missing something?
    >>>
    >>
    >> In the past I have only compiled a kernel with KASAN, compiled the
    >> reproducer program and run it in a VM. No need for the syzbot overhead.
    >
    > Yes, if C program reproducer the crash then it's easier to use.
    > repro.c.txt is the C program, you need to rename it to repro.c,
    > compile with gcc and run just as ./a.out.
    > But make sure that you have a gcc that supports KASAN (kernel build
    > does not in the beginning on compiler not supporting KASAN). I think
    > it's at least gcc 5+, but gcc 7+ would be better.

    I was using gcc 5+ and "gcc repro.c".
    Running ./a.out does not show any issue on dmesg. Let me switch to gcc 7+.

    >
    > You can also run the syzkaller reproducer as:
    > ./syz-execprog -cover=0 -repeat=0 -procs=16 repro.syz.txt

    When using repro.syz.txt, which binary or what tests does it execute?
    I didn't see it uses/compiles the repro.c.txt.
    But it seems to run something...
    ~/net-next# ./syz-execprog -cover=0 -repeat=0 -procs=2 repro.syz.txt
    2018/01/23 11:15:24 parsed 1 programs
    2018/01/23 11:15:24 executed programs: 0
    2018/01/23 11:15:29 executed programs: 210
    2018/01/23 11:15:34 executed programs: 422
    ..

    Thanks
    William

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