From: Benjamin Marzinski Date: Tue, 2 Jul 2024 10:13:24 +0000 (+0200) Subject: dm init: Handle minors larger than 255 X-Git-Tag: v5.10.226~57 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8a7ef20bf7389002e1ce4eab280116c80de798d0;p=thirdparty%2Fkernel%2Fstable.git 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 Signed-off-by: Mikulas Patocka Signed-off-by: Sasha Levin --- diff --git a/drivers/md/dm-init.c b/drivers/md/dm-init.c index b0c45c6ebe0bf..f76477044ec1e 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 */