From 22af286a2976339b25e11c23ac273e1781138fb7 Mon Sep 17 00:00:00 2001 From: Andrew Yourtchenko Date: Thu, 25 Mar 2021 14:13:47 +0000 Subject: [PATCH] acl: fix the integer overflow bug in API message length validation logic Sending the bogus acl_add_replace message with count=~0 will result in an overflow of "expected_len" field which is a u32, thus the message will pass the validation when it should not. Solution - make the expected_len a u64 to avoid overflow. The bug was found while experimenting with libfuzzer as part of https://gerrit.fd.io/r/c/vpp/+/31763 Type: fix Change-Id: I4a866d48f2418148236f1b1d77c487b869c7c43d Signed-off-by: Andrew Yourtchenko --- src/plugins/acl/acl.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/plugins/acl/acl.c b/src/plugins/acl/acl.c index ba4243c6926..dcca2a2c9ba 100644 --- a/src/plugins/acl/acl.c +++ b/src/plugins/acl/acl.c @@ -1772,7 +1772,7 @@ macip_acl_interface_add_del_acl (u32 sw_if_index, u8 is_add, * */ static int -verify_message_len (void *mp, u32 expected_len, char *where) +verify_message_len (void *mp, u64 expected_len, char *where) { u32 supplied_len = vl_msg_api_get_msg_length (mp); if (supplied_len < expected_len) @@ -1796,7 +1796,7 @@ vl_api_acl_add_replace_t_handler (vl_api_acl_add_replace_t * mp) 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]); + u64 expected_len = sizeof (*mp) + acl_count * sizeof (mp->r[0]); if (verify_message_len (mp, expected_len, "acl_add_replace")) { @@ -2085,7 +2085,7 @@ vl_api_macip_acl_add_t_handler (vl_api_macip_acl_add_t * mp) int rv; u32 acl_list_index = ~0; u32 acl_count = ntohl (mp->count); - u32 expected_len = sizeof (*mp) + acl_count * sizeof (mp->r[0]); + u64 expected_len = sizeof (*mp) + acl_count * sizeof (mp->r[0]); if (verify_message_len (mp, expected_len, "macip_acl_add")) { @@ -2112,7 +2112,7 @@ vl_api_macip_acl_add_replace_t_handler (vl_api_macip_acl_add_replace_t * mp) 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]); + u64 expected_len = sizeof (*mp) + acl_count * sizeof (mp->r[0]); if (verify_message_len (mp, expected_len, "macip_acl_add_replace")) { -- 2.16.6