From: Michal Hocko <mhocko@suse.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>,
shy828301@gmail.com, rientjes@google.com, willy@infradead.org,
hannes@cmpxchg.org, guro@fb.com, riel@surriel.com,
minchan@kernel.org, kirill@shutemov.name, aarcange@redhat.com,
brauner@kernel.org, christian@brauner.io, hch@infradead.org,
oleg@redhat.com, david@redhat.com, jannh@google.com,
shakeelb@google.com, luto@kernel.org,
christian.brauner@ubuntu.com, fweimer@redhat.com,
jengelh@inai.de, timmurray@google.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kernel-team@android.com,
syzbot+2ccf63a4bd07cf39cab0@syzkaller.appspotmail.com,
Liam Howlett <liam.howlett@oracle.com>
Subject: Re: [PATCH 1/1] mm: fix use-after-free bug when mm->mmap is reused after being freed
Date: Fri, 25 Feb 2022 11:17:34 +0100 [thread overview]
Message-ID: <YhisviDOip+axLDe@dhcp22.suse.cz> (raw)
In-Reply-To: <20220224201859.a38299b6c9d52cb51e6738ea@linux-foundation.org>
On Thu 24-02-22 20:18:59, Andrew Morton wrote:
> On Tue, 15 Feb 2022 12:19:22 -0800 Suren Baghdasaryan <surenb@google.com> wrote:
>
> > After exit_mmap frees all vmas in the mm, mm->mmap needs to be reset,
> > otherwise it points to a vma that was freed and when reused leads to
> > a use-after-free bug.
> >
> > ...
> >
> > --- a/mm/mmap.c
> > +++ b/mm/mmap.c
> > @@ -3186,6 +3186,7 @@ void exit_mmap(struct mm_struct *mm)
> > vma = remove_vma(vma);
> > cond_resched();
> > }
> > + mm->mmap = NULL;
> > mmap_write_unlock(mm);
> > vm_unacct_memory(nr_accounted);
> > }
>
> After the Maple tree patches, mm_struct.mmap doesn't exist. So I'll
> revert this fix as part of merging the maple-tree parts of linux-next.
> I'll be sending this fix to Linus this week.
But this is a regression introduced in this release cycle so the patch
should be merged before Maple tree patches, no?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2022-02-25 10:17 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-15 20:19 [PATCH 1/1] mm: fix use-after-free bug when mm->mmap is reused after being freed Suren Baghdasaryan
2022-02-15 20:26 ` Rik van Riel
2022-02-15 20:37 ` Andrew Morton
2022-02-15 20:45 ` Suren Baghdasaryan
2022-02-15 20:46 ` Suren Baghdasaryan
2022-02-15 20:51 ` Andrew Morton
2022-02-15 20:42 ` Yang Shi
2022-02-16 7:54 ` Michal Hocko
2022-02-17 19:51 ` Suren Baghdasaryan
2022-02-17 20:50 ` Andrew Morton
2022-02-18 8:11 ` Michal Hocko
2022-02-18 8:10 ` Michal Hocko
2022-02-25 4:18 ` Andrew Morton
2022-02-25 4:23 ` Matthew Wilcox
2022-02-25 5:50 ` Suren Baghdasaryan
2022-03-10 15:55 ` Liam Howlett
2022-03-10 16:28 ` Suren Baghdasaryan
2022-03-10 22:22 ` Liam Howlett
2022-03-10 23:31 ` Suren Baghdasaryan
2022-03-11 1:34 ` Liam Howlett
2022-02-25 10:17 ` Michal Hocko [this message]
2022-02-26 1:04 ` Andrew Morton
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