This is a note to let you know that I've just added the patch titled
block: add check of 'minors' and 'first_minor' 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-add-check-of-minors-and-first_minor-in-device_.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 2e7ea35199c93dd109d423d01df89db12efc1732
Author: Li Nan <linan122@xxxxxxxxxx>
Date: Tue Dec 19 15:59:42 2023 +0800
block: add check of 'minors' and 'first_minor' in device_add_disk()
[ Upstream commit 4c434392c4777881d01beada6701eff8c76b43fe ]
'first_minor' represents the starting minor number of disks, and
'minors' represents the number of partitions in the device. Neither
of them can be greater than MINORMASK + 1.
Commit e338924bd05d ("block: check minor range in device_add_disk()")
only added the check of 'first_minor + minors'. However, their sum might
be less than MINORMASK but their values are wrong. Complete the checks now.
Fixes: e338924bd05d ("block: check minor range in device_add_disk()")
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Link: https://lore.kernel.org/r/20231219075942.840255-1-linan666@xxxxxxxxxxxxxxx
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 6aef540bbacf..84f5ac627e79 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -421,7 +421,9 @@ 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)
+ if (disk->first_minor > MINORMASK ||
+ disk->minors > MINORMASK + 1 ||
+ disk->first_minor + disk->minors > MINORMASK + 1)
return -EINVAL;
} else {
if (WARN_ON(disk->minors))
