[Qemu-devel] [PATCH for-2.9] sheepdog: Fix crash in co_read_response()

[Kevin Wolf <kwolf@redhat.com>]

This fixes a regression introduced in commit 9d456654.

aio_co_wake() can only be used to reenter a coroutine that was already
previously entered, otherwise co->ctx is uninitialised and we access
garbage. Using it immediately after qemu_coroutine_create() like in
co_read_response() is wrong and causes segfaults.

Replace the call with aio_co_enter(), which gets an explicit AioContext
parameter and works even for new coroutines.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
---
 block/sheepdog.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/sheepdog.c b/block/sheepdog.c
index 1b71fc8..142eb4f 100644
--- a/block/sheepdog.c
+++ b/block/sheepdog.c
@@ -942,7 +942,7 @@ static void co_read_response(void *opaque)
         s->co_recv = qemu_coroutine_create(aio_read_response, opaque);
     }
 
-    aio_co_wake(s->co_recv);
+    aio_co_enter(s->aio_context, s->co_recv);
 }
 
 static void co_write_request(void *opaque)
-- 
1.8.3.1