Zebediah Figura : quartz/systemclock: Avoid using the sink structure pointer as a cookie.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 76e6fc92f9988acb0d3f96d8e9b7887a3e7db396
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=76e6fc92f9988acb0d3f96d8e...

Author: Zebediah Figura 
Date:   Sat Mar 16 09:11:47 2019 -0500

quartz/systemclock: Avoid using the sink structure pointer as a cookie.

The same pointer address may be allocated to multiple different structures.

Signed-off-by: Zebediah Figura 
Signed-off-by: Alexandre Julliard

---

dlls/quartz/systemclock.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/dlls/quartz/systemclock.c b/dlls/quartz/systemclock.c
index 0cc6d87..f41cdbe 100644
--- a/dlls/quartz/systemclock.c
+++ b/dlls/quartz/systemclock.c
@@ -26,11 +26,14 @@

WINE_DEFAULT_DEBUG_CHANNEL(quartz);

+static int cookie_counter;
+
 struct advise_sink
 {
     struct list entry;
     HANDLE handle;
     REFERENCE_TIME due_time, period;
+    int cookie;
 };

typedef struct SystemClockImpl {
@@ -228,6 +231,7 @@ static HRESULT WINAPI SystemClockImpl_AdviseTime(IReferenceClock *iface,
     sink->handle = (HANDLE)event;
     sink->due_time = base + offset;
     sink->period = 0;
+    sink->cookie = InterlockedIncrement(&cookie_counter);

EnterCriticalSection(&clock->cs);
     insert_advise_sink(sink, &clock->single_sinks);
@@ -235,7 +239,7 @@ static HRESULT WINAPI SystemClockImpl_AdviseTime(IReferenceClock *iface,

notify_thread(clock);

-    *cookie = (DWORD_PTR)sink;
+    *cookie = sink->cookie;
     return S_OK;
 }

@@ -263,6 +267,7 @@ static HRESULT WINAPI SystemClockImpl_AdvisePeriodic(IReferenceClock* iface,
     sink->handle = (HANDLE)semaphore;
     sink->due_time = start;
     sink->period = period;
+    sink->cookie = InterlockedIncrement(&cookie_counter);

EnterCriticalSection(&clock->cs);
     insert_advise_sink(sink, &clock->periodic_sinks);
@@ -270,7 +275,7 @@ static HRESULT WINAPI SystemClockImpl_AdvisePeriodic(IReferenceClock* iface,

notify_thread(clock);

-    *cookie = (DWORD_PTR)sink;
+    *cookie = sink->cookie;
     return S_OK;
 }

@@ -285,7 +290,7 @@ static HRESULT WINAPI SystemClockImpl_Unadvise(IReferenceClock *iface, DWORD_PTR

LIST_FOR_EACH_ENTRY(sink, &clock->single_sinks, struct advise_sink, entry)
     {
-        if (sink == (struct advise_sink *)cookie)
+        if (sink->cookie == cookie)
         {
             list_remove(&sink->entry);
             heap_free(sink);
@@ -296,7 +301,7 @@ static HRESULT WINAPI SystemClockImpl_Unadvise(IReferenceClock *iface, DWORD_PTR

LIST_FOR_EACH_ENTRY(sink, &clock->periodic_sinks, struct advise_sink, entry)
     {
-        if (sink == (struct advise_sink *)cookie)
+        if (sink->cookie == cookie)
         {
             list_remove(&sink->entry);
             heap_free(sink);