From: Vlastimil Babka <vbabka@suse.cz>
To: Michal Hocko <mhocko@suse.com>, Muchun Song <songmuchun@bytedance.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Shakeel Butt <shakeelb@google.com>, Roman Gushchin <guro@fb.com>,
Stephen Rothwell <sfr@canb.auug.org.au>,
alex.shi@linux.alibaba.com, alexander.h.duyck@linux.intel.com,
Yafang Shao <laoar.shao@gmail.com>,
richard.weiyang@gmail.com, LKML <linux-kernel@vger.kernel.org>,
Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [External] Re: [PATCH] mm/memcg: fix NULL pointer dereference at workingset_eviction
Date: Mon, 30 Nov 2020 16:57:37 +0100 [thread overview]
Message-ID: <eab0b852-9f62-5fc3-6a2f-aae358bc3a98@suse.cz> (raw)
In-Reply-To: <20201130134514.GL17338@dhcp22.suse.cz>
On 11/30/20 2:45 PM, Michal Hocko wrote:
> On Mon 30-11-20 21:36:49, Muchun Song wrote:
>> On Mon, Nov 30, 2020 at 9:23 PM Michal Hocko <mhocko@suse.com> wrote:
>> >
>> > On Mon 30-11-20 21:15:12, Muchun Song wrote:
>> > > We found a case of kernel panic. The stack trace is as follows
>> > > (omit some irrelevant information):
>> > >
>> > > BUG: kernel NULL pointer dereference, address: 00000000000000c8
>> > > RIP: 0010:workingset_eviction+0x26b/0x450
>> > > Call Trace:
>> > > __remove_mapping+0x224/0x2b0
>> > > shrink_page_list+0x8c2/0x14e0
>> > > shrink_inactive_list+0x1bf/0x3f0
>> > > ? do_raw_spin_unlock+0x49/0xc0
>> > > ? _raw_spin_unlock+0xa/0x20
>> > > shrink_lruvec+0x401/0x640
>> > >
>> > > This was caused by commit 76761ffa9ea1 ("mm/memcg: bail out early when
>> > > !memcg in mem_cgroup_lruvec"). When the parameter of memcg is NULL, we
>> > > should not use the &pgdat->__lruvec. So this just reverts commit
>> > > 76761ffa9ea1 to fix it.
>> > >
>> > > Fixes: 76761ffa9ea1 ("mm/memcg: bail out early when !memcg in mem_cgroup_lruvec")
>> >
>> > I do not see any commits like that in the current Linus tree. Is this a
>> > commit id from the linux-next? If yes, can we just fold it into the
>> > respective patch in mmotm tree please?
>>
>> Yes. This commit is on the linux-next tree.
>
> FYI, patches coming from mmotm are constantly rebased in linux-next so
> the sha1 is meaningless and shouldn't be added as a reference in the
> changelog.
>
>> Of course can.
>
> Thanks! I believe Andrew should be able to just pick up the patch and
> make it -fix patch.
Well the fix is a revert, so just remove the patch from mmotm/next?
BTW, looks like it wasn't sent to linux-mm [1], looks like missing To: header.
[1]
https://lore.kernel.org/lkml/1606446515-36069-1-git-send-email-alex.shi@linux.alibaba.com/
next prev parent reply other threads:[~2020-11-30 15:57 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-30 13:15 Muchun Song
2020-11-30 13:23 ` Michal Hocko
2020-11-30 13:36 ` [External] " Muchun Song
2020-11-30 13:45 ` Michal Hocko
2020-11-30 15:57 ` Vlastimil Babka [this message]
2020-11-30 20:23 ` Andrew Morton
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