From: Michal Hocko <mhocko@kernel.org>
To: Peter Xu <peterx@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
syzbot+693dc11fcb53120b5559@syzkaller.appspotmail.com
Subject: Re: [PATCH 1/2] mm/mempolicy: Allow lookup_node() to handle fatal signal
Date: Wed, 8 Apr 2020 12:21:28 +0200 [thread overview]
Message-ID: <20200408102128.GX18914@dhcp22.suse.cz> (raw)
In-Reply-To: <20200408014010.80428-2-peterx@redhat.com>
On Tue 07-04-20 21:40:09, Peter Xu wrote:
> lookup_node() uses gup to pin the page and get node information. It
> checks against ret>=0 assuming the page will be filled in. However
> it's also possible that gup will return zero, for example, when the
> thread is quickly killed with a fatal signal. Teach lookup_node() to
> gracefully return an error -EFAULT if it happens.
>
> Meanwhile, initialize "page" to NULL to avoid potential risk of
> exploiting the pointer.
>
> Reported-by: syzbot+693dc11fcb53120b5559@syzkaller.appspotmail.com
> Fixes: 4426e945df58 ("mm/gup: allow VM_FAULT_RETRY for multiple times")
I am not familiar with thic commit but shouldn't gup return ERESTARTSYS
on a fatal signal?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-04-08 10:21 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 1:40 [PATCH 0/2] mm: Two small fixes for recent syzbot reports Peter Xu
2020-04-08 1:40 ` [PATCH 1/2] mm/mempolicy: Allow lookup_node() to handle fatal signal Peter Xu
2020-04-08 10:21 ` Michal Hocko [this message]
2020-04-08 14:20 ` Peter Xu
2020-04-08 14:30 ` Michal Hocko
2020-04-08 15:24 ` Peter Xu
2020-04-08 15:26 ` Michal Hocko
2020-04-09 7:02 ` Michal Hocko
2020-04-09 12:52 ` Peter Xu
2020-04-09 13:00 ` Peter Xu
2020-04-09 13:53 ` Michal Hocko
2020-04-09 16:42 ` Linus Torvalds
2020-04-14 11:04 ` Michal Hocko
2020-04-14 13:49 ` Peter Xu
2020-04-14 14:18 ` Michal Hocko
2020-04-20 12:47 ` Michal Hocko
2020-04-20 17:31 ` Linus Torvalds
2020-04-21 7:09 ` Michal Hocko
2020-04-08 1:40 ` [PATCH 2/2] mm/gup: Mark lock taken only after a successful retake Peter Xu
2020-04-09 0:47 ` [PATCH 0/2] mm: Two small fixes for recent syzbot reports Andrew Morton
2020-04-09 11:49 ` Matthew Wilcox
2020-04-09 13:00 ` Dmitry Vyukov
2020-04-09 18:16 ` Andrew Morton
2020-04-09 18:53 ` Linus Torvalds
2020-04-09 19:12 ` Andrew Morton
2020-04-09 19:46 ` Linus Torvalds
2020-04-09 19:56 ` Matthew Wilcox
2020-04-09 19:58 ` Linus Torvalds
2020-04-09 20:27 ` Eric Biggers
2020-04-09 20:34 ` Linus Torvalds
2020-04-09 23:34 ` Stephen Rothwell
2020-04-10 1:11 ` Theodore Y. Ts'o
2020-04-09 12:55 ` Dmitry Vyukov
2020-04-09 16:32 ` Linus Torvalds
2020-04-09 16:58 ` Qian Cai
2020-04-09 17:05 ` Linus Torvalds
2020-04-09 17:58 ` Qian Cai
2020-04-09 18:06 ` Linus Torvalds
2020-04-09 21:14 ` Qian Cai
2020-04-10 13:12 ` Tetsuo Handa
2020-04-10 14:26 ` Qian Cai
2020-04-10 17:26 ` Andrew Morton
2020-04-10 19:46 ` Qian Cai
2020-04-09 23:29 ` Stephen Rothwell
2020-04-13 22:06 ` Qian Cai
2020-04-13 23:05 ` Jens Axboe
2020-04-14 11:12 ` Dmitry Vyukov
2020-04-14 11:59 ` Qian Cai
2020-04-14 12:05 ` Dmitry Vyukov
2020-04-14 19:28 ` Dan Rue
2020-04-15 11:09 ` Dmitry Vyukov
2020-04-15 16:23 ` Dan Rue
2020-04-16 0:34 ` Stephen Rothwell
2020-05-11 15:29 ` Dmitry Vyukov
2020-04-14 4:07 ` Hillf Danton
2020-04-14 4:31 ` Jens Axboe
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