Review at https://gerrit.osmocom.org/7841
ipa_asp_fsm: Prevent against integer underflow
Ensure we don't pass a negative integer as "unsigned int len" to
ipa_asp_fsm_wait_id_get(). This could result in a remotely-triggered
integer underflow.
Change-Id: Idf9a5c0938e6ae6d47bf85ddfec3306fa3ddb3ce
---
M src/xua_asp_fsm.c
1 file changed, 5 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmo-sccp refs/changes/41/7841/1
diff --git a/src/xua_asp_fsm.c b/src/xua_asp_fsm.c
index e81f0af..93c76cb 100644
--- a/src/xua_asp_fsm.c
+++ b/src/xua_asp_fsm.c
@@ -881,6 +881,11 @@
data_len = msgb_l2len(msg_get)-1;
LOGPFSM(fi, "Received IPA CCM IDENTITY REQUEST for IEs %s\n",
osmo_hexdump(req_data, data_len));
+ /* avoid possible unsigned integer underflow, as
ipa_ccm_make_id_resp_from_req()
+ * expects an unsigned integer, and in case of a zero-length L2
message we might
+ * have data_len == -1 here */
+ if (data_len < 0)
+ data_len = 0;
/* Send ID_RESP to server */
msg_resp = ipa_ccm_make_id_resp_from_req(iafp->ipa_unit,
req_data, data_len);
if (!msg_resp) {
--
To view, visit https://gerrit.osmocom.org/7841
To unsubscribe, visit https://gerrit.osmocom.org/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: Idf9a5c0938e6ae6d47bf85ddfec3306fa3ddb3ce
Gerrit-PatchSet: 1
Gerrit-Project: libosmo-sccp
Gerrit-Branch: master
Gerrit-Owner: Harald Welte <[email protected]>
