Re: [PATCH] md/raid10: fix divide-by-zero in setup_geo() with zero far_copies

["Yu Kuai" <yukuai@fnnas.com>]

Hi,

在 2026/4/19 13:59, Yuhao Jiang 写道:
> Hi Kuai,
>
> This report was reported by me, so Junrui added me as Reported-by.

This is fine, however, please do not add downstream reported-by tag.
If you want to add the reported-by tag, please report the problem to
patchwork first. :)

>
> Thanks,
>
> On Sun, Apr 19, 2026 at 12:43 AM Yu Kuai <yukuai@fnnas.com> wrote:
>
>     Hi,
>
>     在 2026/4/16 11:39, Junrui Luo 写道:
>     > setup_geo() extracts near_copies (nc) and far_copies (fc) from the
>     > user-provided layout parameter without checking for zero. When fc=0
>     > with the "improved" far set layout selected, 'geo->far_set_size =
>     > disks / fc' triggers a divide-by-zero.
>     >
>     > Validate nc and fc immediately after extraction, returning -1 if
>     > either is zero.
>     >
>     > Fixes: 475901aff158 ("MD RAID10: Improve redundancy for 'far'
>     and 'offset' algorithms (part 1)")
>     > Reported-by: Yuhao Jiang<danisjiang@gmail.com>
>
>     So again I can't find a report, and Reported-by usually should be
>     followed
>     by a Closes link to the original report.
>
>     Applied with Reported-by tag removed.
>
>     > Cc:stable@vger.kernel.org <mailto:Cc%3Astable@vger.kernel.org>
>     > Signed-off-by: Junrui Luo<moonafterrain@outlook.com>
>     > ---
>     >   drivers/md/raid10.c | 2 ++
>     >   1 file changed, 2 insertions(+)
>
>     -- 
>     Thansk,
>     Kuai
>
>
>
> -- 
> Yuhao Jiang

-- 
Thansk,
Kuai