dm ioctl: validate name length when renaming

When renaming a mapped device validate the length of the new name.

The rename ioctl accepted any correctly-terminated string enclosed
within the data passed from userspace.  The other ioctls enforce a
size limit of DM_NAME_LEN.  If the name is changed and becomes longer
than that, the device can no longer be addressed by name.

Fix it by properly checking for device name length (including
terminating zero).

Cc: stable@kernel.org
Signed-off-by: Milan Broz <mbroz@redhat.com>
Reviewed-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Milan Broz 2009-03-16 16:56:01 +00:00 committed by Alasdair G Kergon
parent 5bee17f18b
commit bc0fd67feb
1 changed files with 2 additions and 1 deletions

View File

@ -704,7 +704,8 @@ static int dev_rename(struct dm_ioctl *param, size_t param_size)
char *new_name = (char *) param + param->data_start;
if (new_name < param->data ||
invalid_str(new_name, (void *) param + param_size)) {
invalid_str(new_name, (void *) param + param_size) ||
strlen(new_name) > DM_NAME_LEN - 1) {
DMWARN("Invalid new logical volume name supplied.");
return -EINVAL;
}