[pulseaudio-discuss] [PATCH 1/2] memblock: Detect block ID collisions in pa_memimport_get

[David Henningsson]

Make sure we don't hand out the wrong block, in case we have the
same block ID in different SHM segments.

Signed-off-by: David Henningsson <david.henningsson at canonical.com>
---
 src/pulsecore/memblock.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/pulsecore/memblock.c b/src/pulsecore/memblock.c
index f8b008f..ca24dec 100644
--- a/src/pulsecore/memblock.c
+++ b/src/pulsecore/memblock.c
@@ -1017,6 +1017,11 @@ pa_memblock* pa_memimport_get(pa_memimport *i, uint32_t block_id, uint32_t shm_i
     pa_mutex_lock(i->mutex);
 
     if ((b = pa_hashmap_get(i->blocks, PA_UINT32_TO_PTR(block_id)))) {
+        if (b->type != PA_MEMBLOCK_IMPORTED || b->per_type.imported.segment->memory.id != shm_id) {
+            pa_log("Cannot import memory due to to block ID collision (block %d, shm id %d)!", (int) block_id, (int) shm_id);
+            b = NULL;
+            goto finish;
+        }
         pa_memblock_ref(b);
         goto finish;
     }
-- 
1.9.1