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Stop policy timer before invoking session destructor

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The CDM session was being destroyed before the policy timer was stopped
and before the session was removed from a list of active sessions. This
allowed race conditions, where the policy timer would try to evaluate
policy for a closed session. This led to segfaults.
b/11338324

Merge of https://widevine-internal-review.googlesource.com/#/c/8240/1
from the widevine cdm repo.

Change-Id: Ib159ccfdb763a47da573f5c06c0793c2c63886c4
This commit is contained in:
Jeff Tinker
2013-10-25 10:50:02 -07:00
parent 6fc2ee33c3
commit 49e593d127
2 changed files with 8 additions and 6 deletions
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2
libwvdrmengine/cdm/core/include/cdm_engine.h
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@@ -114,7 +114,7 @@ class CdmEngine : public TimerHandler {
// timer related methods to drive policy decisions
virtual void EnablePolicyTimer();
virtual void DisablePolicyTimer();
virtual void DisablePolicyTimer(bool force);
virtual void OnTimerEvent();
virtual void OnKeyReleaseEvent(const CdmKeySetId& key_set_id);

12
libwvdrmengine/cdm/core/src/cdm_engine.cpp
View File

@@ -29,6 +29,7 @@ CdmEngine::CdmEngine()
CdmEngine::~CdmEngine() {
CancelSessions();
DisablePolicyTimer(true);
CdmSessionMap::iterator i(sessions_.begin());
for (; i != sessions_.end(); ++i)
delete i->second;
@@ -98,9 +99,10 @@ CdmResponseType CdmEngine::CloseSession(const CdmSessionId& session_id) {
return KEY_ERROR;
}
delete iter->second;
CdmSession* session = iter->second;
sessions_.erase(session_id);
DisablePolicyTimer();
DisablePolicyTimer(false);
delete session;
return NO_ERROR;
}
@@ -295,7 +297,7 @@ CdmResponseType CdmEngine::CancelKeyRequest(const CdmSessionId& session_id) {
}
// TODO(edwinwong, rfrias): unload keys here
DisablePolicyTimer();
DisablePolicyTimer(false);
return NO_ERROR;
}
@@ -675,8 +677,8 @@ void CdmEngine::EnablePolicyTimer() {
policy_timer_.Start(this, kCdmPolicyTimerDurationSeconds);
}
void CdmEngine::DisablePolicyTimer() {
if (sessions_.size() == 0 && policy_timer_.IsRunning())
void CdmEngine::DisablePolicyTimer(bool force) {
if ((sessions_.size() == 0 || force) && policy_timer_.IsRunning())
policy_timer_.Stop();
}