Re: UBSAN: shift-out-of-bounds in ext4_fill_super

[Dmitry Vyukov]

On Thu, Dec 10, 2020 at 7:28 PM Theodore Y. Ts'o <tytso@xxxxxxx> wrote:
>
> On Thu, Dec 10, 2020 at 09:09:51AM +0100, Dmitry Vyukov wrote:
> > >  * [new tag]                   ext4-for-linus-5.8-rc1-2 -> ext4-for-linus-5.8-rc1-2
> > >  ! [rejected]                  ext4_for_linus           -> ext4_for_linus  (would clobber existing tag)
> >
> > Interesting. First time I see this. Should syzkaller use 'git fetch
> > --tags --force"?...
> > StackOverflow suggests it should help:
> > https://stackoverflow.com/questions/58031165/how-to-get-rid-of-would-clobber-existing-tag
>
> Yeah, sorry, ext4_for_linus is a signed tag which is only used to
> authenticate my pull request to Linus.  After Linus accepts the pull,
> the digital signature is going to be upstream, and so I end up
> deleting and the reusing that tag for the next merge window.
>
> I guess I could just start always using ext4_for_linus-<VERSION> and
> just delete the tags once they have been accepted, to keep my list of
> tags clean.
>
> It's going to make everyone else's tags who pull from ext4.git messy,
> though, with gobs of tags that probably won't be of use to them.  It
> does avoid the need to use git fetch --tags --force, and I guess
> people are used to the need to GC tags with the linux-repo.  So maybe
> that's the right thing to do going forward.

Hi Ted,

syzbot is now prepared and won't fail next time, nor on other similar
trees. Which is good.
So it's really up to you.

Thanks