Huw Davies : winealsa: Don't acquire the sessions lock after the client lock.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 1acba9d959377074110cc05a74e47f9af3f5005d
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=1acba9d959377074110cc05a7...

Author: Huw Davies 
Date:   Thu Dec  2 12:02:38 2021 +0000

winealsa: Don't acquire the sessions lock after the client lock.

This could lead to a deadlock with AudioSessionControl_GetState()
which acquires the locks in the other order.

Signed-off-by: Huw Davies 
Signed-off-by: Andrew Eikum 
Signed-off-by: Alexandre Julliard

---

dlls/winealsa.drv/mmdevdrv.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c
index 7f25cdcce1b..5aa1b4aab63 100644
--- a/dlls/winealsa.drv/mmdevdrv.c
+++ b/dlls/winealsa.drv/mmdevdrv.c
@@ -1344,10 +1344,12 @@ static HRESULT WINAPI AudioClient_Initialize(IAudioClient3 *iface,
         }
     }

+    EnterCriticalSection(&g_sessions_lock);
     EnterCriticalSection(&This->lock);

if(This->initted){
         LeaveCriticalSection(&This->lock);
+        LeaveCriticalSection(&g_sessions_lock);
         return AUDCLNT_E_ALREADY_INITIALIZED;
     }

@@ -1537,19 +1539,13 @@ static HRESULT WINAPI AudioClient_Initialize(IAudioClient3 *iface,
     This->share = mode;
     This->flags = flags;

-    EnterCriticalSection(&g_sessions_lock);
-
     hr = get_audio_session(sessionguid, This->parent, fmt->nChannels,
             &This->session);
-    if(FAILED(hr)){
-        LeaveCriticalSection(&g_sessions_lock);
+    if(FAILED(hr))
         goto exit;
-    }

list_add_tail(&This->session->clients, &This->entry);

-    LeaveCriticalSection(&g_sessions_lock);
-
     This->initted = TRUE;

TRACE("ALSA period: %lu frames\n", This->alsa_period_frames);
@@ -1569,6 +1565,7 @@ exit:
     }

LeaveCriticalSection(&This->lock);
+    LeaveCriticalSection(&g_sessions_lock);

return hr;
 }