diff options
| author | Naoya Horiguchi <naoya.horiguchi@nec.com> | 2022-09-08 13:11:50 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-10-12 09:53:28 +0200 |
| commit | 0fa249414a6fa863383834624bd030fb0fc7fa23 (patch) | |
| tree | a9128ec8a01844e6b9ba621fb22419b67c3c26d3 /mm | |
| parent | f1d6894159fc4164647f6b0e9a0a49b18ae64feb (diff) | |
mm/huge_memory: use pfn_to_online_page() in split_huge_pages_all()
[ Upstream commit 2b7aa91ba0e86b8643f5d3c83874c80599c731d7 ]
NULL pointer dereference is triggered when calling thp split via debugfs
on the system with offlined memory blocks. With debug option enabled, the
following kernel messages are printed out:
page:00000000467f4890 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x121c000
flags: 0x17fffc00000000(node=0|zone=2|lastcpupid=0x1ffff)
raw: 0017fffc00000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: unmovable page
page:000000007d7ab72e is uninitialized and poisoned
page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:1248!
invalid opcode: 0000 [#1] PREEMPT SMP PTI
CPU: 16 PID: 20964 Comm: bash Tainted: G I 6.0.0-rc3-foll-numa+ #41
...
RIP: 0010:split_huge_pages_write+0xcf4/0xe30
This shows that page_to_nid() in page_zone() is unexpectedly called for an
offlined memmap.
Use pfn_to_online_page() to get struct page in PFN walker.
Link: https://lkml.kernel.org/r/20220908041150.3430269-1-naoya.horiguchi@linux.dev
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") [visible after d0dc12e86b319]
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Co-developed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: <stable@vger.kernel.org> [5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 34d2979489fd..07941a1540cb 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2885,11 +2885,9 @@ static void split_huge_pages_all(void) max_zone_pfn = zone_end_pfn(zone); for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { int nr_pages; - if (!pfn_valid(pfn)) - continue; - page = pfn_to_page(pfn); - if (!get_page_unless_zero(page)) + page = pfn_to_online_page(pfn); + if (!page || !get_page_unless_zero(page)) continue; if (zone != page_zone(page)) |