[PATCH] mm/memory-failure: reject unsupported non-folio compound page
From: Miaohe Lin <linmiaohe@huawei.com>
Date: 2026-02-05 07:43:10
Also in:
lkml
Subsystem:
hwpoison memory failure handling, memory management, the rest · Maintainers:
Miaohe Lin, Andrew Morton, Linus Torvalds
When !CONFIG_TRANSPARENT_HUGEPAGE, a non-folio compound page can appear in
a userspace mapping via either vm_insert_*() functions or
vm_operatios_struct->fault(). They are not folios, thus should not be
considered for folio operations like split. To reject these pages, make
sure get_hwpoison_page() is always called as HWPoisonHandlable() will do
the right work.
Fixes: 689b8986776c ("mm/memory-failure: improve large block size folio handling")
Reported-by: 是参差 <redacted>
Closes: https://lore.kernel.org/all/PS1PPF7E1D7501F1E4F4441E7ECD056DEADAB98A@PS1PPF7E1D7501F.apcprd02.prod.outlook.com/ (local)
Reviewed-by: Zi Yan <ziy@nvidia.com>
Tested-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
[Some commit log borrowed from Zi Yan [off-list ref]. Thanks.]
---
mm/memory-failure.c | 42 ++++++++++++++++++++----------------------
1 file changed, 20 insertions(+), 22 deletions(-)
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 825c706ac576..ba4231858a36 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c@@ -2411,31 +2411,29 @@ int memory_failure(unsigned long pfn, int flags) * In fact it's dangerous to directly bump up page count from 0, * that may make page_ref_freeze()/page_ref_unfreeze() mismatch. */ - if (!(flags & MF_COUNT_INCREASED)) { - res = get_hwpoison_page(p, flags); - if (!res) { - if (is_free_buddy_page(p)) { - if (take_page_off_buddy(p)) { - page_ref_inc(p); - res = MF_RECOVERED; - } else { - /* We lost the race, try again */ - if (retry) { - ClearPageHWPoison(p); - retry = false; - goto try_again; - } - res = MF_FAILED; - } - res = action_result(pfn, MF_MSG_BUDDY, res); + res = get_hwpoison_page(p, flags); + if (!res) { + if (is_free_buddy_page(p)) { + if (take_page_off_buddy(p)) { + page_ref_inc(p); + res = MF_RECOVERED; } else { - res = action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); + /* We lost the race, try again */ + if (retry) { + ClearPageHWPoison(p); + retry = false; + goto try_again; + } + res = MF_FAILED; } - goto unlock_mutex; - } else if (res < 0) { - res = action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED); - goto unlock_mutex; + res = action_result(pfn, MF_MSG_BUDDY, res); + } else { + res = action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); } + goto unlock_mutex; + } else if (res < 0) { + res = action_result(pfn, MF_MSG_GET_HWPOISON, MF_IGNORED); + goto unlock_mutex; } folio = page_folio(p);
--
2.33.0