From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>, <pasha.tatashin@soleen.com>
Cc: <rientjes@google.com>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>, <linmiaohe@huawei.com>
Subject: [PATCH] mm/page_table_check: fix accessing unmapped ptep
Date: Thu, 26 May 2022 19:33:50 +0800 [thread overview]
Message-ID: <20220526113350.30806-1-linmiaohe@huawei.com> (raw)
ptep is unmapped too early, so ptep will be accessed while it's unmapped.
Fix it by deferring pte_unmap() until page table checking is done.
Fixes: 80110bbfbba6 ("mm/page_table_check: check entries at pmd levels")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/page_table_check.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 3692bea2ea2c..971c3129b0e3 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -234,11 +234,11 @@ void __page_table_check_pte_clear_range(struct mm_struct *mm,
pte_t *ptep = pte_offset_map(&pmd, addr);
unsigned long i;
- pte_unmap(ptep);
for (i = 0; i < PTRS_PER_PTE; i++) {
__page_table_check_pte_clear(mm, addr, *ptep);
addr += PAGE_SIZE;
ptep++;
}
+ pte_unmap(ptep);
}
}
--
2.23.0
next reply other threads:[~2022-05-26 11:33 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-26 11:33 Miaohe Lin [this message]
2022-05-26 13:04 ` Qi Zheng
2022-05-26 13:11 ` Pasha Tatashin
2022-05-26 13:23 ` Qi Zheng
2022-05-26 13:17 ` Pasha Tatashin
2022-05-26 13:34 ` Matthew Wilcox
2022-05-26 13:37 ` Pasha Tatashin
2022-05-26 18:15 ` Andrew Morton
2022-05-26 18:31 ` Pasha Tatashin
2022-05-27 1:10 ` Miaohe Lin
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