From f75868e020a1d03f87d49e9cd2cc349a45249f29 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Fri, 17 Dec 2021 23:51:25 +0900 Subject: block: check minor range in device_add_disk() [ Upstream commit e338924bd05d6e71574bc13e310c89e10e49a8a5 ] ioctl(fd, LOOP_CTL_ADD, 1048576) causes sysfs: cannot create duplicate filename '/dev/block/7:0' message because such request is treated as if ioctl(fd, LOOP_CTL_ADD, 0) due to MINORMASK == 1048575. Verify that all minor numbers for that device fit in the minor range. Reported-by: wangyangbo Signed-off-by: Tetsuo Handa Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/b1b19379-23ee-5379-0eb5-94bf5f79f1b4@i-love.sakura.ne.jp Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/genhd.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'block') diff --git a/block/genhd.c b/block/genhd.c index 22f899615801..de789d1a1e3d 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -420,6 +420,8 @@ int 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) + return -EINVAL; } else { if (WARN_ON(disk->minors)) return -EINVAL; -- cgit v1.2.3