ews: add missing locking for concurrent EWSPlugin::unsubscribe invocation

jengelh · jengelh · commit 1a42e7ab8bea · 2025-11-05T10:51:13.000+01:00
``` =21176==ERROR: AddressSanitizer: heap-buffer-overflow .. READ of size 8 line numbers relative to commit ad84c9f f0 std::string::size() const f1 unsigned long FNV::operator()<std::string>(std::string const&) exch/ews/ews.cpp:1170 f2 FNV& FNV::operator<< <std::string>(std::string const&) exch/ews/hash.hpp:101 f3 FNV::FNV<std::string, unsigned int>(std::string const&, unsigned int const&) exch/ews/hash.hpp:48 f4 std::hash<ExmdbSubscriptionKey>::operator()(ExmdbSubscriptionKey const&) const exch/ews/ews.cpp:1185 f5 std::__detail::_Hash_code_base<ExmdbSubscriptionKey>::_M_hash_code(ExmdbSubscriptionKey const&) const f6 std::__detail::_Hash_code_base<ExmdbSubscriptionKey>::_M_bucket_index(std::__detail::_Hash_node_value<std::pair<ExmdbSubscriptionKey const, unsigned int>, false> const&, unsigned long) const f7 std::_Hashtable<ExmdbSubscriptionKey>::_M_bucket_index(std::__detail::_Hash_node_value<std::pair<ExmdbSubscriptionKey const, unsigned int>, false> const&) const f8 std::_Hashtable<ExmdbSubscriptionKey>::_M_erase(unsigned long, std::__detail::_Hash_node_base*, std::__detail::_Hash_node<std::pair<ExmdbSubscriptionKey const, unsigned int>, false>*) f9 std::_Hashtable<ExmdbSubscriptionKey>::_M_erase(std::integral_constant<bool, true>, ExmdbSubscriptionKey const&) f10 std::_Hashtable<ExmdbSubscriptionKey>::erase(ExmdbSubscriptionKey const&) f11 std::unordered_map<ExmdbSubscriptionKey, unsigned int>::erase(ExmdbSubscriptionKey const&) f12 EWSPlugin::unsubscribe(ExmdbSubscriptionKey const&) const exch/ews/ews.cpp:1084 f13 EWSPlugin::SubManager::~SubManager() exch/ews/ews.cpp:766 f14 void std::destroy_at(EWSPlugin::SubManager*) f15 void std::_Destroy(EWSPlugin::SubManager*) f16 void std::allocator_traits::destroy(std::allocator<void>&, EWSPlugin::SubManager*) f17 std::_Sp_counted_ptr_inplace<EWSPlugin::SubManager>::_M_dispose() f18 std::_Sp_counted_base::_M_release() f19 std::__shared_count::~__shared_count() f20 std::__shared_ptr<EWSPlugin::SubManager>::~__shared_ptr() f21 std::shared_ptr<EWSPlugin::SubManager>::~shared_ptr() f22 EWSPlugin::unsubscribe(unsigned int, char const*) const exch/ews/ews.cpp:1073 f23 EWSContext::unsubscribe(Structures::tSubscriptionId const&) const exch/ews/context.cpp:2618 f24 EWSContext::~EWSContext() exch/ews/context.cpp:393 f25 std::default_delete::operator()(EWSContext*) const f26 std::__uniq_ptr_impl::reset(EWSContext*) f27 std::unique_ptr::reset(EWSContext*) f28 EWSPlugin::term(int) exch/ews/ews.cpp:726 f29 operator() exch/ews/ews.cpp:561 f30 _FUN exch/ews/ews.cpp:561 f31 hpm_processor_insert_ctx(http_context*) exch/http/hpm_processor.cpp:501 f32 wrrep_nobuf exch/http/http_parser.cpp:1525 f33 wrrep exch/http/http_parser.cpp:1617 f34 http_parser_process(schedule_context*) exch/http/http_parser.cpp:2217 f35 tpol_thrwork lib/threads_pool.cpp:201 ``` References: GXL-503, GXL-648, DESK-4196
diff --git a/exch/ews/ews.cpp b/exch/ews/ews.cpp
@@ -1079,7 +1079,10 @@ bool EWSPlugin::unsubscribe(detail::SubscriptionKey subscriptionKey,
  */
 void EWSPlugin::unsubscribe(const detail::ExmdbSubscriptionKey& key) const
 {
-	subscriptions.erase(key);
+	{
+		std::unique_lock lk(subscriptionLock);
+		subscriptions.erase(key);
+	}
 	exmdb.unsubscribe_notification(key.first.c_str(), key.second);
 }
 

Original file line number	Diff line number	Diff line change
`@@ -1079,7 +1079,10 @@ bool EWSPlugin::unsubscribe(detail::SubscriptionKey subscriptionKey,`
`1079`	`1079`	`*/`
`1080`	`1080`	`void EWSPlugin::unsubscribe(const detail::ExmdbSubscriptionKey& key) const`
`1081`	`1081`	`{`
`1082`		`- subscriptions.erase(key);`
	`1082`	`+ {`
	`1083`	`+ std::unique_lock lk(subscriptionLock);`
	`1084`	`+ subscriptions.erase(key);`
	`1085`	`+ }`
`1083`	`1086`	`exmdb.unsubscribe_notification(key.first.c_str(), key.second);`
`1084`	`1087`	`}`
`1085`	`1088`