Re: [syzbot] [bpf?] KMSAN: uninit-value in trie_delete_elem

[Aleksandr Nogikh]

On Wed, Apr 3, 2024 at 5:59 AM Yonghong Song <yonghong.song@xxxxxxxxx> wrote:
>
>
> On 4/1/24 11:36 PM, Aleksandr Nogikh wrote:
> > Hi,
> >
> > On Mon, Apr 1, 2024 at 8:55 PM Yonghong Song <yonghong.song@xxxxxxxxx> wrote:
> >>
> >> On 3/26/24 12:00 PM, syzbot wrote:
> >>> Hello,
> >>>
> >>> syzbot found the following issue on:
> >>>
> >>> =====================================================
> >>> BUG: KMSAN: uninit-value in trie_delete_elem+0xc0/0xbe0 kernel/bpf/lpm_trie.c:448
> >> Unrelated to the bug itself, with KMSAN is enabled, qemu cannot boot my vm
> >> any more. Anything special I need to do in order to boot a KMSAN kernel?
> >>
> > Does the kernel print any specific errors to the serial console while
> > booting? Or nothing at all?
>
> In my case, nothing at all.
>

If you're using qemu, please try adding "-machine pc-q35-7.1" to its
arguments. Otherwise it's known to have problems with very large
kernel images.

-- 
Aleksandr