Re: [PATCH 3.19 091/123] gadgetfs: use-after-free in ->aio_read()

[Alexander Holler]

Am 25.03.2015 um 11:15 schrieb Greg Kroah-Hartman:
> On Wed, Mar 25, 2015 at 10:23:27AM +0100, Alexander Holler wrote:
> > Am 25.03.2015 um 09:33 schrieb Greg Kroah-Hartman:

> > > Is there a specific patch that is in Linus's tree that fixes this issue
> > > that I should be applying to the stable tree?
> >
> > No specific one. The changes of this patch were discarded by other patches
> > in Linus tree which fixed other problems of gadgetfs too.
> >
> > Besides that the solution for this one specific patch is a one-liner, I'll
> > give a short overview:
> >
> > - gadgetfs is already unusable since 3.16 (even with this patch) because
> > (p)read/(p)write doesn't work (fixed with 4.0)
> > - the problem this patch fixes is unlikely to be hit because glibc doesn't
> > use the Linux aio-syscall, but pread/pwrite, which means someone has to use
> > a special lib and not aio(7) to end up at the syscall the patch in question
> > fixes.
> > - there aren't that many users of gadgetfs
> >
> > No idea if you want to apply or backport the whole series found in Al Viros
> > vfs.git/gadgetfs.
>
> As this has been broken since 3.16, and no one has taken the time to fix
> it since then, it's not really an issue here, people can just use 4.0 if
> they want it.

Just a hint I think which should be kept in mind: Debian still uses 
something below 3.16, which very likely is the reason why nobody has hit 
(and examined) these bugs before.

Regards,

Alexander Holler
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