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authorDave Barach <dave@barachs.net>2020-04-29 17:04:10 -0400
committerFlorin Coras <florin.coras@gmail.com>2020-05-04 14:03:21 +0000
commit7784140f2bd2d5ae44f2be1507ac25f102006155 (patch)
tree4ac12e04f5177bffab6f3c05d6bf837567a65988 /src/plugins/dhcp/dhcp_api.c
parentd88fc0fcedb402e3dc82cb44280d4567a6a13266 (diff)
misc: binary api fuzz test fixes
Add a hook to src/vlibapi/api_shared.c to fuzz (screw up) binary API messages, e.g. by xoring random data into them before processing. We specifically exempt client connection messages, and inband debug CLI messages. We step over msg_id, client index, client context, and sw_if_index. Otherwise, "make test" vectors fail too rapidly to learn anything. The goal is to reduce the number of crashes caused to zero. We're fairly close with this patch. Add vl_msg_api_max_length(void *mp), which returns the maximum plausible length for a binary API message. Use it to hardern vl_api_from_api_to_new_vec(...) which takes an additional argument - message pointer - so it can verify that astr->length is sane. If it's not sane, return a u8 *vector of the form "insane astr->length nnnn\0". Verify array lengths in vl_api_dhcp6_send_client_message_t_handler(...) and vl_api_dhcp6_pd_send_client_message_t_handler(...). Add a fairly effective binary API fuzz hook to the unittest plugin, and modify the "make test" framework.py to pass "api-fuzz { on|off }" to enable API fuzzing: "make API_FUZZ=on TEST=xxx test-debug" or similar Type: improvement Signed-off-by: Dave Barach <dave@barachs.net> Change-Id: I0157267652a163c01553d5267620f719cc6c3bde
Diffstat (limited to 'src/plugins/dhcp/dhcp_api.c')
-rw-r--r--src/plugins/dhcp/dhcp_api.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/src/plugins/dhcp/dhcp_api.c b/src/plugins/dhcp/dhcp_api.c
index a5163ca2e95..d2e423572fb 100644
--- a/src/plugins/dhcp/dhcp_api.c
+++ b/src/plugins/dhcp/dhcp_api.c
@@ -549,6 +549,12 @@ void
params.T1 = ntohl (mp->T1);
params.T2 = ntohl (mp->T2);
n_addresses = ntohl (mp->n_addresses);
+ /* Make sure that the number of addresses is sane */
+ if (n_addresses * sizeof (params.addresses) > vl_msg_api_max_length (mp))
+ {
+ rv = VNET_API_ERROR_INVALID_VALUE;
+ goto bad_sw_if_index;
+ }
params.addresses = 0;
if (n_addresses > 0)
vec_validate (params.addresses, n_addresses - 1);
@@ -593,6 +599,14 @@ void
params.T1 = ntohl (mp->T1);
params.T2 = ntohl (mp->T2);
n_prefixes = ntohl (mp->n_prefixes);
+
+ /* Minimal check to see that the number of prefixes is sane */
+ if (n_prefixes * sizeof (params.prefixes) > vl_msg_api_max_length (mp))
+ {
+ rv = VNET_API_ERROR_INVALID_VALUE;
+ goto bad_sw_if_index;
+ }
+
params.prefixes = 0;
if (n_prefixes > 0)
vec_validate (params.prefixes, n_prefixes - 1);