From: Tetsuo Handa penguin-kernel@i-love.sakura.ne.jp
[ 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@uniontech.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/b1b19379-23ee-5379-0eb5-94bf5f79f1b4@i-love.sakura... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- block/genhd.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/block/genhd.c b/block/genhd.c index f091a60dcf1ea..2eabe4c459fe1 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;