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From:   Zhong Jinghua <zhongjinghua@huaweicloud.com>
To:     axboe@kernel.dk, penguin-kernel@i-love.sakura.ne.jp
Cc:     linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
        zhongjinghua@huawei.com, yi.zhang@huawei.com, yukuai3@huawei.com
Subject: [PATCH] block: Fix minor range check in device_add_disk()
Date:   Wed, 25 Oct 2023 16:46:21 +0800
Message-Id: <20231025084621.2338604-1-zhongjinghua@huaweicloud.com>
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From: Zhong Jinghua <zhongjinghua@huawei.com>

Checks added in patch:
commit e338924bd05d ("block: check minor range in device_add_disk()")
ignore the problem of first_minore < 0 and disk->minors < 0.

Fix it by adding first_minore < 0 and disk->minors < 0 check.

Fixes: e338924bd05d ("block: check minor range in device_add_disk()")
Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
---
 block/genhd.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/block/genhd.c b/block/genhd.c
index 736215e9ddc3..8292a1e265cf 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -432,7 +432,9 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 				DISK_MAX_PARTS);
 			disk->minors = DISK_MAX_PARTS;
 		}
-		if (disk->first_minor + disk->minors > MINORMASK + 1)
+		if (disk->first_minor > MINORMASK ||
+			disk->minors > (1U << MINORBITS) ||
+			disk->first_minor + disk->minors > MINORMASK + 1)
 			goto out_exit_elevator;
 	} else {
 		if (WARN_ON(disk->minors))
-- 
2.31.1