block: check minor range in device_add_disk()
authorTetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Fri, 17 Dec 2021 14:51:25 +0000 (23:51 +0900)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 27 Jan 2022 10:04:48 +0000 (11:04 +0100)
commitf75868e020a1d03f87d49e9cd2cc349a45249f29
tree0129a3ba61c5f07e9358df64554724ab39e46fee
parent892805138cb49f0db59c44f38c6998d8a2137fce
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@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.ne.jp
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
block/genhd.c