From be2cd261ca510be5cb51b198c602c516207dd32b Mon Sep 17 00:00:00 2001
From: Minchan Kim <minchan@kernel.org>
Date: Thu, 8 Sep 2022 08:12:04 -0700
Subject: [PATCH] mm: fix madivse_pageout mishandling on non-LRU page
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commit 58d426a7ba92870d489686dfdb9d06b66815a2ab upstream.
MADV_PAGEOUT tries to isolate non-LRU pages and gets a warning from
isolate_lru_page below.
Fix it by checking PageLRU in advance.
------------[ cut here ]------------
trying to isolate tail page
WARNING: CPU: 0 PID: 6175 at mm/folio-compat.c:158 isolate_lru_page+0x130/0x140
Modules linked in:
CPU: 0 PID: 6175 Comm: syz-executor.0 Not tainted 5.18.12 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:isolate_lru_page+0x130/0x140
Link: https://lore.kernel.org/linux-mm/485f8c33.2471b.182d5726afb.Coremail.hantianshuo@iie.ac.cn/
Link: https://lkml.kernel.org/r/20220908151204.762596-1-minchan@kernel.org
Fixes: 1a4e58cce84e ("mm: introduce MADV_PAGEOUT")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: 韩天ç` <hantianshuo@iie.ac.cn>
Suggested-by: Yang Shi <shy828301@gmail.com>
Acked-by: Yang Shi <shy828301@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
mm/madvise.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/mm/madvise.c b/mm/madvise.c
index 77e1dc2d4e18..f71fc88f0b33 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -434,8 +434,11 @@ regular_page:
continue;
}
- /* Do not interfere with other mappings of this page */
- if (page_mapcount(page) != 1)
+ /*
+ * Do not interfere with other mappings of this page and
+ * non-LRU page.
+ */
+ if (!PageLRU(page) || page_mapcount(page) != 1)
continue;
VM_BUG_ON_PAGE(PageTransCompound(page), page);