diff options
| -rw-r--r-- | src/plugins/acl/acl.c | 45 |
1 files changed, 42 insertions, 3 deletions
diff --git a/src/plugins/acl/acl.c b/src/plugins/acl/acl.c index 4f3c54e8..6b79411e 100644 --- a/src/plugins/acl/acl.c +++ b/src/plugins/acl/acl.c @@ -1079,6 +1079,34 @@ macip_acl_interface_add_del_acl (u32 sw_if_index, u8 is_add, return rv; } +/* + * If the client does not allocate enough memory for a variable-length + * message, and then proceed to use it as if the full memory allocated, + * absent the check we happily consume that on the VPP side, and go + * along as if nothing happened. However, the resulting + * effects range from just garbage in the API decode + * (because the decoder snoops too far), to potential memory + * corruptions. + * + * This verifies that the actual length of the message is + * at least expected_len, and complains loudly if it is not. + * + * A failing check here is 100% a software bug on the API user side, + * so we might as well yell. + * + */ +static int verify_message_len(void *mp, u32 expected_len, char *where) +{ + u32 supplied_len = vl_msg_api_get_msg_length (mp); + if (supplied_len < expected_len) { + clib_warning("%s: Supplied message length %d is less than expected %d", + where, supplied_len, expected_len); + return 0; + } else { + return 1; + } +} + /* API message handler */ static void vl_api_acl_add_replace_t_handler (vl_api_acl_add_replace_t * mp) @@ -1087,8 +1115,14 @@ vl_api_acl_add_replace_t_handler (vl_api_acl_add_replace_t * mp) acl_main_t *am = &acl_main; int rv; u32 acl_list_index = ntohl (mp->acl_index); + u32 acl_count = ntohl (mp->count); + u32 expected_len = sizeof(*mp) + acl_count*sizeof(mp->r[0]); - rv = acl_add_list (ntohl (mp->count), mp->r, &acl_list_index, mp->tag); + if (verify_message_len(mp, expected_len, "acl_add_replace")) { + rv = acl_add_list (acl_count, mp->r, &acl_list_index, mp->tag); + } else { + rv = VNET_API_ERROR_INVALID_VALUE; + } /* *INDENT-OFF* */ REPLY_MACRO2(VL_API_ACL_ADD_REPLACE_REPLY, @@ -1344,9 +1378,14 @@ vl_api_macip_acl_add_t_handler (vl_api_macip_acl_add_t * mp) acl_main_t *am = &acl_main; int rv; u32 acl_list_index = ~0; + u32 acl_count = ntohl (mp->count); + u32 expected_len = sizeof(*mp) + acl_count*sizeof(mp->r[0]); - rv = - macip_acl_add_list (ntohl (mp->count), mp->r, &acl_list_index, mp->tag); + if (verify_message_len(mp, expected_len, "macip_acl_add")) { + rv = macip_acl_add_list (acl_count, mp->r, &acl_list_index, mp->tag); + } else { + rv = VNET_API_ERROR_INVALID_VALUE; + } /* *INDENT-OFF* */ REPLY_MACRO2(VL_API_MACIP_ACL_ADD_REPLY, |