[PATCH BlueZ v1] bass: Fix crashing on BT_BASS_MOD_SRC

[Luiz Augusto von Dentz <luiz.dentz@gmail.com>]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

If assistant attempt o modify source the code would attempt to iterate
over all valid range of BIS indexes which may lead to the following
trace since the delegator maybe freed in the process:

 #0  queue_find (queue=<optimized out>, function=function@entry=0x58b8761109c0 <setup_match_bis>, match_data=match_data@entry=0x3) at src/shared/queue.c:230
 #1  0x000058b8761127fb in bass_update_bis_sync (bcast_src=<optimized out>, dg=<optimized out>) at profiles/audio/bass.c:1824
 #2  handle_mod_src_req (data=<optimized out>, params=<optimized out>, bcast_src=0x58b894661be0) at profiles/audio/bass.c:1862
 #3  cp_handler (bcast_src=0x58b894661be0, op=<optimized out>, params=<optimized out>, user_data=<optimized out>) at profiles/audio/bass.c:1910
 #4  0x000058b8761bc978 in bass_handle_mod_src_op (bass=<optimized out>, attrib=<optimized out>, opcode=<optimized out>, id=<optimized out>, iov=<optimized out>, att=<optimized out>)
    at src/shared/bass.c:1069

To fix the code will now just interate at existing setups checking if
they match the BIS index then adding/removing the stream so it is no
longer possible to free the delegator before all setups are processed.
---
 profiles/audio/bass.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/profiles/audio/bass.c b/profiles/audio/bass.c
index bf0db0555963..e3710ea04c2b 100644
--- a/profiles/audio/bass.c
+++ b/profiles/audio/bass.c
@@ -1865,21 +1865,21 @@ static bool setup_match_bis(const void *data, const void *match_data)
 static void bass_update_bis_sync(struct bass_delegator *dg,
 				struct bt_bcast_src *bcast_src)
 {
-	for (int bis = 1; bis < ISO_MAX_NUM_BIS; bis++) {
-		struct bass_setup *setup = queue_find(dg->setups,
-				setup_match_bis, INT_TO_PTR(bis));
-		uint8_t state;
+	struct queue_entry *entry;
 
-		if (!setup)
-			continue;
+	/* Check if existing setups if BIS needs to be added/removed */
+	for (entry = queue_get_entries(dg->setups); entry;
+				entry = entry->next) {
+		struct bass_setup *setup = entry->data;
+		uint8_t state;
 
 		state = bt_bap_stream_get_state(setup->stream);
 
-		if (!setup->stream && bt_bass_check_bis(bcast_src, bis))
+		if (!setup->stream && bt_bass_check_bis(bcast_src, setup->bis))
 			bass_add_bis(setup);
 		else if (setup->stream &&
 				state == BT_BAP_STREAM_STATE_STREAMING &&
-				!bt_bass_check_bis(bcast_src, bis))
+				!bt_bass_check_bis(bcast_src, setup->bis))
 			bass_remove_bis(setup);
 	}
 }
-- 
2.53.0