Messages in this thread Patch in this message | | | From | Demi Marie Obenour <> | Subject | [PATCH v2 5/6] device-mapper: Refuse to create device named "control" | Date | Sat, 3 Jun 2023 10:52:43 -0400 |
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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@invisiblethingslab.com> --- 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 7510afe237d979a5ee71afe87a20d49f631de1aa..5b647ab044e44b0c9d0961b5a336b41f50408f88 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -767,7 +767,12 @@ 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
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