Re: [Linux-kernel-mentees] [PATCH net] ethtool: strset: Fix out of bound read in strset_parse_request()

[Anmol karn]

Hello sir,
On Sun, Oct 11, 2020 at 10:24 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Sun, 11 Oct 2020 02:39:29 +0530 Anmol Karn wrote:
> > Flag ``ETHTOOL_A_STRSET_COUNTS_ONLY`` tells the kernel to only return the string
> > counts of the sets, but, when req_info->counts_only tries to read the
> > tb[ETHTOOL_A_STRSET_COUNTS_ONLY] it gets out of bound.
> >
> > - net/ethtool/strset.c
> > The bug seems to trigger in this line:
> >
> > req_info->counts_only = tb[ETHTOOL_A_STRSET_COUNTS_ONLY];
> >
> > Fix it by NULL checking for req_info->counts_only while
> > reading from tb[ETHTOOL_A_STRSET_COUNTS_ONLY].
> >
> > Reported-by: syzbot+9d1389df89299fa368dc@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Link: https://syzkaller.appspot.com/bug?id=730deff8fe9954a5e317924d9acff98d9c64a770
> > Signed-off-by: Anmol Karn <anmol.karan123@xxxxxxxxx>
>
> I think the correct fix for this was already applied to net-next as:
>
>  commit db972e532518 ("ethtool: strset: allow ETHTOOL_A_STRSET_COUNTS_ONLY attr")

I am glad that it's fixed now.

Thanks,
Anmol