From 5f0e3f8bf1710f23eaa223357e41a8595487094b Mon Sep 17 00:00:00 2001 From: Dimitri Staessens Date: Fri, 1 May 2026 14:38:23 +0200 Subject: ipcpd: Validate wire frame lengths Asserting frame lengths coming from the wire was a severe flaw. Fixed by gracefully dropping runt frames. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders --- src/ipcpd/udp/udp.c | 9 ++++++--- src/ipcpd/unicast/fa.c | 7 ++++--- 2 files changed, 10 insertions(+), 6 deletions(-) (limited to 'src/ipcpd') diff --git a/src/ipcpd/udp/udp.c b/src/ipcpd/udp/udp.c index 452bbc1a..168ea718 100644 --- a/src/ipcpd/udp/udp.c +++ b/src/ipcpd/udp/udp.c @@ -352,13 +352,18 @@ static int udp_ipcp_mgmt_frame(struct __SOCKADDR c_saddr, qosspec_t qs; buffer_t data; + /* Defence against malformed/corrupted wire input. */ + if (len < sizeof(*msg)) + return -1; + msg = (struct mgmt_msg *) buf; switch (msg->code) { case FLOW_REQ: msg_len = sizeof(*msg) + ipcp_dir_hash_len(); - assert(len >= msg_len); + if (len < msg_len) + return -1; data.len = len - msg_len; data.data = (uint8_t *) buf + msg_len; @@ -377,8 +382,6 @@ static int udp_ipcp_mgmt_frame(struct __SOCKADDR c_saddr, (uint8_t *) (msg + 1), qs, &data); case FLOW_REPLY: - assert(len >= sizeof(*msg)); - data.len = len - sizeof(*msg); data.data = (uint8_t *) buf + sizeof(*msg); diff --git a/src/ipcpd/unicast/fa.c b/src/ipcpd/unicast/fa.c index c157d71c..f398d317 100644 --- a/src/ipcpd/unicast/fa.c +++ b/src/ipcpd/unicast/fa.c @@ -528,7 +528,8 @@ static int fa_handle_flow_reply(struct fa_msg * msg, time_t mpl = IPCP_UNICAST_MPL; int response; - assert(len >= sizeof(*msg)); + if (len < sizeof(*msg)) + return -EINVAL; data.data = (uint8_t *) msg + sizeof(*msg); data.len = len - sizeof(*msg); @@ -572,8 +573,8 @@ static int fa_handle_flow_update(struct fa_msg * msg, struct fa_flow * flow; int fd; - (void) len; - assert(len >= sizeof(*msg)); + if (len < sizeof(*msg)) + return -EINVAL; pthread_rwlock_wrlock(&fa.flows_lock); -- cgit v1.2.3