[Asterisk-code-review] AST-2019-004 - res_pjsip_t38.c: Add NULL checks before using session ... (...asterisk[16.5])
George Joseph
asteriskteam at digium.com
Thu Sep 5 07:49:45 CDT 2019
George Joseph has submitted this change and it was merged. ( https://gerrit.asterisk.org/c/asterisk/+/12840 )
Change subject: AST-2019-004 - res_pjsip_t38.c: Add NULL checks before using session media
......................................................................
AST-2019-004 - res_pjsip_t38.c: Add NULL checks before using session media
After receiving a 200 OK with a declined stream in response to a T.38
initiated re-invite Asterisk would crash when attempting to dereference
a NULL session media object.
This patch checks to make sure the session media object is not NULL before
attempting to use it.
ASTERISK-28495
patches:
ast-2019-004.patch submitted by Alexei Gradinari (license 5691)
Change-Id: I168f45f4da29cfe739acf87e597baa2aae7aa572
---
M res/res_pjsip_t38.c
1 file changed, 45 insertions(+), 27 deletions(-)
Approvals:
George Joseph: Looks good to me, approved; Approved for Submit
diff --git a/res/res_pjsip_t38.c b/res/res_pjsip_t38.c
index 11804e2..e5c6090 100644
--- a/res/res_pjsip_t38.c
+++ b/res/res_pjsip_t38.c
@@ -203,7 +203,6 @@
{
RAII_VAR(struct ast_sip_session *, session, obj, ao2_cleanup);
RAII_VAR(struct ast_datastore *, datastore, ast_sip_session_get_datastore(session, "t38"), ao2_cleanup);
- struct ast_sip_session_media *session_media;
if (!datastore) {
return 0;
@@ -212,8 +211,7 @@
ast_debug(2, "Automatically rejecting T.38 request on channel '%s'\n",
session->channel ? ast_channel_name(session->channel) : "<gone>");
- session_media = session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(session, session_media, datastore->data, T38_REJECTED);
+ t38_change_state(session, NULL, datastore->data, T38_REJECTED);
ast_sip_session_resume_reinvite(session);
return 0;
@@ -322,28 +320,37 @@
int index;
session_media = session->active_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(session, session_media, state, T38_ENABLED);
+ if (!session_media) {
+ ast_log(LOG_WARNING, "Received %d response to T.38 re-invite on '%s' but no active session media\n",
+ status.code, session->channel ? ast_channel_name(session->channel) : "unknown channel");
+ } else {
+ t38_change_state(session, session_media, state, T38_ENABLED);
- /* Stop all the streams in the stored away active state, they'll go back to being active once
- * we reinvite back.
- */
- for (index = 0; index < AST_VECTOR_SIZE(&state->media_state->sessions); ++index) {
- struct ast_sip_session_media *session_media = AST_VECTOR_GET(&state->media_state->sessions, index);
+ /* Stop all the streams in the stored away active state, they'll go back to being active once
+ * we reinvite back.
+ */
+ for (index = 0; index < AST_VECTOR_SIZE(&state->media_state->sessions); ++index) {
+ struct ast_sip_session_media *session_media = AST_VECTOR_GET(&state->media_state->sessions, index);
- if (session_media && session_media->handler && session_media->handler->stream_stop) {
- session_media->handler->stream_stop(session_media);
+ if (session_media && session_media->handler && session_media->handler->stream_stop) {
+ session_media->handler->stream_stop(session_media);
+ }
}
+
+ return 0;
}
} else {
session_media = session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(session, session_media, state, T38_REJECTED);
-
- /* Abort this attempt at switching to T.38 by resetting the pending state and freeing our stored away active state */
- ast_sip_session_media_state_free(state->media_state);
- state->media_state = NULL;
- ast_sip_session_media_state_reset(session->pending_media_state);
}
+ /* If no session_media then response contained a declined stream, so disable */
+ t38_change_state(session, NULL, state, session_media ? T38_REJECTED : T38_DISABLED);
+
+ /* Abort this attempt at switching to T.38 by resetting the pending state and freeing our stored away active state */
+ ast_sip_session_media_state_free(state->media_state);
+ state->media_state = NULL;
+ ast_sip_session_media_state_reset(session->pending_media_state);
+
return 0;
}
@@ -426,12 +433,10 @@
/* Negotiation can not take place without a valid max_ifp value. */
if (!parameters->max_ifp) {
if (data->session->t38state == T38_PEER_REINVITE) {
- session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(data->session, session_media, state, T38_REJECTED);
+ t38_change_state(data->session, NULL, state, T38_REJECTED);
ast_sip_session_resume_reinvite(data->session);
} else if (data->session->t38state == T38_ENABLED) {
- session_media = data->session->active_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(data->session, session_media, state, T38_DISABLED);
+ t38_change_state(data->session, NULL, state, T38_DISABLED);
ast_sip_session_refresh(data->session, NULL, NULL, NULL,
AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, state->media_state);
state->media_state = NULL;
@@ -454,6 +459,11 @@
state->our_parms.version = MIN(state->our_parms.version, state->their_parms.version);
state->our_parms.rate_management = state->their_parms.rate_management;
session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
+ if (!session_media) {
+ ast_log(LOG_ERROR, "Failed to negotiate parameters for reinvite on channel '%s' (No pending session media).\n",
+ data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
+ break;
+ }
ast_udptl_set_local_max_ifp(session_media->udptl, state->our_parms.max_ifp);
t38_change_state(data->session, session_media, state, T38_ENABLED);
ast_sip_session_resume_reinvite(data->session);
@@ -468,8 +478,13 @@
}
state->our_parms = *parameters;
session_media = media_state->default_session[AST_MEDIA_TYPE_IMAGE];
+ if (!session_media) {
+ ast_log(LOG_ERROR, "Failed to negotiate parameters on channel '%s' (No default session media).\n",
+ data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
+ break;
+ }
ast_udptl_set_local_max_ifp(session_media->udptl, state->our_parms.max_ifp);
- t38_change_state(data->session, session_media, state, T38_LOCAL_REINVITE);
+ t38_change_state(data->session, NULL, state, T38_LOCAL_REINVITE);
ast_sip_session_refresh(data->session, NULL, t38_reinvite_sdp_cb, t38_reinvite_response_cb,
AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, media_state);
}
@@ -478,12 +493,10 @@
case AST_T38_REFUSED:
case AST_T38_REQUEST_TERMINATE: /* Shutdown T38 */
if (data->session->t38state == T38_PEER_REINVITE) {
- session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(data->session, session_media, state, T38_REJECTED);
+ t38_change_state(data->session, NULL, state, T38_REJECTED);
ast_sip_session_resume_reinvite(data->session);
} else if (data->session->t38state == T38_ENABLED) {
- session_media = data->session->active_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
- t38_change_state(data->session, session_media, state, T38_DISABLED);
+ t38_change_state(data->session, NULL, state, T38_DISABLED);
ast_sip_session_refresh(data->session, NULL, NULL, NULL, AST_SIP_SESSION_REFRESH_METHOD_INVITE, 1, state->media_state);
state->media_state = NULL;
}
@@ -493,6 +506,11 @@
if (data->session->t38state == T38_PEER_REINVITE) {
session_media = data->session->pending_media_state->default_session[AST_MEDIA_TYPE_IMAGE];
+ if (!session_media) {
+ ast_log(LOG_ERROR, "Failed to request parameters for reinvite on channel '%s' (No pending session media).\n",
+ data->session->channel ? ast_channel_name(data->session->channel) : "unknown channel");
+ break;
+ }
parameters.max_ifp = ast_udptl_get_far_max_ifp(session_media->udptl);
parameters.request_response = AST_T38_REQUEST_NEGOTIATE;
ast_queue_control_data(data->session->channel, AST_CONTROL_T38_PARAMETERS, ¶meters, sizeof(parameters));
@@ -788,7 +806,7 @@
if ((session->t38state == T38_REJECTED) || (session->t38state == T38_DISABLED)) {
ast_debug(3, "Declining; T.38 state is rejected or declined\n");
- t38_change_state(session, session_media, state, T38_DISABLED);
+ t38_change_state(session, NULL, state, T38_DISABLED);
return 0;
}
--
To view, visit https://gerrit.asterisk.org/c/asterisk/+/12840
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Gerrit-Project: asterisk
Gerrit-Branch: 16.5
Gerrit-Change-Id: I168f45f4da29cfe739acf87e597baa2aae7aa572
Gerrit-Change-Number: 12840
Gerrit-PatchSet: 1
Gerrit-Owner: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Kevin Harwell <kharwell at digium.com>
Gerrit-MessageType: merged
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