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From:   linan666@huaweicloud.com
To:     song@kernel.org, neilb@suse.de, Rob.Becker@riverbed.com
Cc:     linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org,
        linan122@huawei.com, yukuai3@huawei.com, yi.zhang@huawei.com,
        houtao1@huawei.com, yangerkun@huawei.com
Subject: [PATCH v2 1/4] md/raid10: fix slab-out-of-bounds in md_bitmap_get_counter
Date:   Sat,  6 May 2023 09:23:12 +0800
Message-Id: <20230506012315.3370489-2-linan666@huaweicloud.com>
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From: Li Nan <linan122@huawei.com>

If we write a large number to md/bitmap_set_bits, md_bitmap_checkpage()
will return -EINVAL because "page >= bitmap->pages", but the return value
was not checked immediately in md_bitmap_get_counter() in order to set
*blocks value and slab-out-of-bounds occurs.

Return directly if err is -EINVAL.

Fixes: ef4256733506 ("md/bitmap: optimise scanning of empty bitmaps.")
Signed-off-by: Li Nan <linan122@huawei.com>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
---
 drivers/md/md-bitmap.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 920bb68156d2..0b41ef422da7 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -1388,6 +1388,8 @@ __acquires(bitmap->lock)
 	int err;
 
 	err = md_bitmap_checkpage(bitmap, page, create, 0);
+	if (err == -EINVAL)
+		return NULL;
 
 	if (bitmap->bp[page].hijacked ||
 	    bitmap->bp[page].map == NULL)
-- 
2.31.1