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From: Shijie Luo <luoshijie1@huawei.com>
To: <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
	<linmiaohe@huawei.com>, <linfeilong@huawei.com>,
	<luoshijie1@huawei.com>
Subject: [PATCH] mm: fix potential pte_unmap_unlock pte error
Date: Thu, 15 Oct 2020 08:15:34 -0400	[thread overview]
Message-ID: <20201015121534.50910-1-luoshijie1@huawei.com> (raw)

When flags don't have MPOL_MF_MOVE or MPOL_MF_MOVE_ALL bits, code breaks
 and passing origin pte - 1 to pte_unmap_unlock seems like not a good idea.

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Signed-off-by: linmiaohe <linmiaohe@huawei.com>
---
 mm/mempolicy.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3fde772ef5ef..01f088630d1d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -571,7 +571,11 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 		} else
 			break;
 	}
-	pte_unmap_unlock(pte - 1, ptl);
+
+	if (addr >= end)
+		pte = pte - 1;
+
+	pte_unmap_unlock(pte, ptl);
 	cond_resched();
 
 	if (has_unmovable)
-- 
2.19.1


             reply	other threads:[~2020-10-15 12:16 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-15 12:15 Shijie Luo [this message]
2020-10-15 12:58 ` [PATCH] mm: fix potential pte_unmap_unlock pte error osalvador
2020-10-15 13:19   ` Shijie Luo
2020-10-16 12:31 ` Michal Hocko
2020-10-16 12:37   ` osalvador
2020-10-16 13:11     ` Michal Hocko
2020-10-16 13:15       ` Michal Hocko
2020-10-16 13:42         ` Michal Hocko
2020-10-16 14:05           ` osalvador
2020-10-17  1:55             ` Shijie Luo
2021-01-09  8:01 [PATCH] mm: Fix " Miaohe Lin
2021-01-10 17:14 ` Andi Kleen
2021-01-14  2:51   ` Miaohe Lin
2021-01-22  8:27     ` Miaohe Lin
2021-01-24  2:01       ` Andrew Morton
2021-01-25  2:04         ` Miaohe Lin

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