Re: [selftest/bpf] b83590ee1a: BUG:KASAN:slab-out-of-bounds_in_l

[Daniel Xu]

Hi Daniel,

On Mon Nov 9, 2020 at 8:54 AM PST, Daniel Borkmann wrote:
> Hi Daniel,
>
> On 11/9/20 3:54 PM, kernel test robot wrote:
> > Greeting,
> > 
> > FYI, we noticed the following commit (built with gcc-9):
> > 
> > commit: b83590ee1add052518603bae607b0524632b7793 ("[PATCH bpf v3 2/2] selftest/bpf: Test bpf_probe_read_user_str() strips trailing bytes after NUL")
> > url: https://github.com/0day-ci/linux/commits/Daniel-Xu/Fix-bpf_probe_read_user_str-overcopying/20201106-033210
> > base: https://git.kernel.org/cgit/linux/kernel/git/bpf/bpf.git master
>
> I've tossed them from the tree for now as it looks like these are adding
> regressions
> for regular strncpy_from_user() calls, please take a look.
>
> Thanks!

Sorry about the KASAN issue.

I spent a day reproing. The kasan warnings seem a bit misleading but I
think I have a fix. I'll put a v5 shortly. I'll see if any of the bots
find errors on it.

Thanks,
Daniel