From f1bc5a86c7cb06dac797d9ea25a2392a84865870 Mon Sep 17 00:00:00 2001 From: Benjamin Marzinski Date: Tue, 2 Jul 2024 12:13:24 +0200 Subject: [PATCH] dm init: Handle minors larger than 255 BugLink: https://bugs.launchpad.net/bugs/2081278 [ 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 Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin Signed-off-by: Koichiro Den Signed-off-by: Stefan Bader --- 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 */