This is a note to let you know that I've just added the patch titled block: check minor range in device_add_disk() to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-check-minor-range-in-device_add_disk.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit fc383923e957d0670e381f94427991a9236d30f4 Author: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Date: Fri Dec 17 23:51:25 2021 +0900 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 <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> diff --git a/block/genhd.c b/block/genhd.c index 22f899615801c..de789d1a1e3d2 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;