Typical userspace setups create a symlink under /dev/mapper with the name of the device, but /dev/mapper/control is reserved for the control device. Therefore, trying to create such a device is almost certain to be a userspace bug. Signed-off-by: Demi Marie Obenour <demi@xxxxxxxxxxxxxxxxxxxxxx> --- drivers/md/dm-ioctl.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 52aa5505d23b2f3d9c0faf6e8a91b74cd7845581..9ae00e3c1a72c19575814cf473774835b364320b 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -771,7 +771,12 @@ static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t static int check_name(const char *name) { if (strchr(name, '/')) { - DMERR("invalid device name"); + DMERR("device name cannot contain '/'"); + return -EINVAL; + } + + if (strcmp(name, DM_CONTROL_NODE) == 0) { + DMERR("device name cannot be \"%s\"", DM_CONTROL_NODE); return -EINVAL; } -- Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab