Messages in this thread | | | Subject | Re: [External] Re: [PATCH] mm/memcg: fix NULL pointer dereference at workingset_eviction | From | Vlastimil Babka <> | Date | Mon, 30 Nov 2020 16:57:37 +0100 |
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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/
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