Commit bc0fd67f authored Mar 16, 2009 by Milan Broz Committed by Alasdair G Kergon Mar 16, 2009

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>

parent 5bee17f1

drivers/md/dm-ioctl.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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;
		}