KEYS: special dot prefixed keyring name bug fix

Dot prefixed keyring names are supposed to be reserved for the
kernel, but add_key() calls key_get_type_from_user(), which
incorrectly verifies the 'type' field, not the 'description' field.
This patch verifies the 'description' field isn't dot prefixed,
when creating a new keyring, and removes the dot prefix test in
key_get_type_from_user().

Changelog v6:
- whitespace and other cleanup

Changelog v5:
- Only prevent userspace from creating a dot prefixed keyring, not
  regular keys  - Dmitry

Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
This commit is contained in:
Mimi Zohar 2014-05-22 14:02:23 -04:00
parent 32c2e6752f
commit a4e3b8d79a
1 changed files with 4 additions and 2 deletions

View File

@ -37,8 +37,6 @@ static int key_get_type_from_user(char *type,
return ret;
if (ret == 0 || ret >= len)
return -EINVAL;
if (type[0] == '.')
return -EPERM;
type[len - 1] = '\0';
return 0;
}
@ -86,6 +84,10 @@ SYSCALL_DEFINE5(add_key, const char __user *, _type,
if (!*description) {
kfree(description);
description = NULL;
} else if ((description[0] == '.') &&
(strncmp(type, "keyring", 7) == 0)) {
ret = -EPERM;
goto error2;
}
}