This is a note to let you know that I've just added the patch titled
dm init: Handle minors larger than 255
to the 5.10-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:
dm-init-handle-minors-larger-than-255.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 91efe177dd708ef630e607f21f86a09b8d9be3d5
Author: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
Date: Tue Jul 2 12:13:24 2024 +0200
dm init: Handle minors larger than 255
[ Upstream commit 140ce37fd78a629105377e17842465258a5459ef ]
dm_parse_device_entry() simply copies the minor number into dmi.dev, but
the dev_t format splits the minor number between the lowest 8 bytes and
highest 12 bytes. If the minor number is larger than 255, part of it
will end up getting treated as the major number
Fix this by checking that the minor number is valid and then encoding it
as a dev_t.
Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
index b0c45c6ebe0b..f76477044ec1 100644
--- a/drivers/md/dm-init.c
+++ b/drivers/md/dm-init.c
@@ -207,8 +207,10 @@ static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
/* minor */
if (strlen(field[2])) {
- if (kstrtoull(field[2], 0, &dev->dmi.dev))
+ if (kstrtoull(field[2], 0, &dev->dmi.dev) ||
+ dev->dmi.dev >= (1 << MINORBITS))
return ERR_PTR(-EINVAL);
+ dev->dmi.dev = huge_encode_dev((dev_t)dev->dmi.dev);
dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
}
/* flags */
