From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> [ 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 <wangyangbo@xxxxxxxxxxxxx> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Link: https://lore.kernel.org/r/b1b19379-23ee-5379-0eb5-94bf5f79f1b4@xxxxxxxxxxxxxxxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- block/genhd.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/block/genhd.c b/block/genhd.c index 30362aeacac4b..b0847f7a90c50 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -425,6 +425,8 @@ 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) + return -EINVAL; } else { if (WARN_ON(disk->minors)) return -EINVAL; -- 2.34.1
