Re: [PATCH 5.4 058/194] mtd: Fix gluebi NULL pointer dereference caused by ftl notifier

[Zhihao Cheng]

在 2024/2/18 18:25, Richard Weinberger 写道:
> ----- Ursprüngliche Mail -----
> > Von: "chengzhihao1" <chengzhihao1@xxxxxxxxxx>
> > > Hi Greg, hi patch-developers,
> > >
> > > wait a second. this already went into v5.4.268 but still: Doesn't this
> > > break userspace?
> > >
> > > According to
> > > https://lore.kernel.org/lkml/441107100.23734.1697904580252.JavaMail.zimbra@xxxxxx/
> > > where this solution seems to come from, the behaviour changes: "no
> > > mtdblock (hence, also no FTLs) on top of gluebi."
> > >
> > > I fell accross this because of an out-of-tree module that does
> > > sys_mount() an mtdblock, so I won't complain about my code specifically
> > > :) But doesn't it break mounting, say, jffs2 inside an ubi via
> > > mtdblock? If so, is this really something that you want to see
> > > backported to old kernels?
> > >
> > > Or differently put: Has this patch been picked up for old stable
> > > kernels by scripts or by a human?
> > >
> > > I just want to make sure, and who knows, it might help others too, who
> > > would just do a (possibly dangerous?) revert in their trees.
> >
> > This change does affect the mounting(mtdblock based on gluebi) behavior
> > in userspace. It was picked into stable versions because the fixed
> > problem is serious and easy to be reproduced, I guess.
> > A temporary solution is that modify mounting source target in userspace,
> > just replace mtdblock with mtd char device. For example, mount -t jffs2
> > mtd0 /mnt
>
> I don't think this needs backporting to stable. It's not serious because you
> still need to be root to setup and trigger such a scenario.


Yes. I feel okay to revert this patch on stable versions.