5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
[ 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>
---
drivers/md/dm-init.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c
index b869316d3722..4a8bbe0391a2 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 */
--
2.43.0
