3.16.44-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Mimi Zohar <[email protected]> commit a4e3b8d79a5c6d40f4a9703abf7fe3abcc6c3b8d upstream. 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 <[email protected]> Signed-off-by: Mimi Zohar <[email protected]> Acked-by: David Howells <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- security/keys/keyctl.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/security/keys/keyctl.c +++ b/security/keys/keyctl.c @@ -37,8 +37,6 @@ static int key_get_type_from_user(char * 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 __us if (!*description) { kfree(description); description = NULL; + } else if ((description[0] == '.') && + (strncmp(type, "keyring", 7) == 0)) { + ret = -EPERM; + goto error2; } }
