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;
