5.15-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Marzinski bmarzins@redhat.com
[ 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@redhat.com Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 dc4381d68313..6e9e73a55874 100644 --- a/drivers/md/dm-init.c +++ b/drivers/md/dm-init.c @@ -213,8 +213,10 @@ 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 */