From: Naoya Horiguchi <naoya.horiguchi@nec.com> mainline inclusion from linux-v5.10-rc1 commit fd476720c9ba3cf16617d074a94a0852be468545 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4LE22 CVE: NA -------------------------------- Another memory error injection interface debugfs:hwpoison/corrupt-pfn also takes bogus refcount for hwpoison_filter(). It's justified because this does a coarse filter, expecting that memory_failure() redoes the check for sure. Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Ma Wupeng <mawupeng1@huawei.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- mm/hwpoison-inject.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff --git a/mm/hwpoison-inject.c b/mm/hwpoison-inject.c index b6ac70616c321..766062ce62a21 100644 --- a/mm/hwpoison-inject.c +++ b/mm/hwpoison-inject.c @@ -25,11 +25,6 @@ static int hwpoison_inject(void *data, u64 val) p = pfn_to_page(pfn); hpage = compound_head(p); - /* - * This implies unable to support free buddy pages. - */ - if (!get_hwpoison_page(p)) - return 0; if (!hwpoison_filter_enable) goto inject; @@ -39,23 +34,20 @@ static int hwpoison_inject(void *data, u64 val) * This implies unable to support non-LRU pages. */ if (!PageLRU(hpage) && !PageHuge(p)) - goto put_out; + return 0; /* - * do a racy check with elevated page count, to make sure PG_hwpoison - * will only be set for the targeted owner (or on a free page). + * do a racy check to make sure PG_hwpoison will only be set for + * the targeted owner (or on a free page). * memory_failure() will redo the check reliably inside page lock. */ err = hwpoison_filter(hpage); if (err) - goto put_out; + return 0; inject: pr_info("Injecting memory failure at pfn %#lx\n", pfn); - return memory_failure(pfn, MF_COUNT_INCREASED); -put_out: - put_hwpoison_page(p); - return 0; + return memory_failure(pfn, 0); } static int hwpoison_unpoison(void *data, u64 val) -- 2.25.1