From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
If there are pending request while disconnecting they would be notified
but clients may endup being freed in the proccess which will then be
calling bt_att_cancel to cancal its requests causing the following
trace:
Invalid read of size 4
at 0x1D894C: enable_ccc_callback (gatt-client.c:1627)
by 0x1D247B: disc_att_send_op (att.c:417)
by 0x1CCC17: queue_remove_all (queue.c:354)
by 0x1D47B7: disconnect_cb (att.c:635)
by 0x1E0707: watch_callback (io-glib.c:170)
by 0x48E963B: g_main_context_dispatch (in /usr/lib/libglib-2.0.so.0.6400.4)
by 0x48E9AC7: ??? (in /usr/lib/libglib-2.0.so.0.6400.4)
by 0x48E9ECF: g_main_loop_run (in /usr/lib/libglib-2.0.so.0.6400.4)
by 0x1E0E97: mainloop_run (mainloop-glib.c:79)
by 0x1E13B3: mainloop_run_with_signal (mainloop-notify.c:201)
by 0x12BC3B: main (main.c:770)
Address 0x7d40a28 is 24 bytes inside a block of size 32 free'd
at 0x484A2E0: free (vg_replace_malloc.c:540)
by 0x1CCC17: queue_remove_all (queue.c:354)
by 0x1CCC83: queue_destroy (queue.c:73)
by 0x1D7DD7: bt_gatt_client_free (gatt-client.c:2209)
by 0x16497B: batt_free (battery.c:77)
by 0x16497B: batt_remove (battery.c:286)
by 0x1A0013: service_remove (service.c:176)
by 0x1A9B7B: device_remove_gatt_service (device.c:3691)
by 0x1A9B7B: gatt_service_removed (device.c:3805)
by 0x1CC90B: queue_foreach (queue.c:220)
by 0x1DE27B: notify_service_changed.isra.0.part.0 (gatt-db.c:369)
by 0x1DE387: notify_service_changed (gatt-db.c:361)
by 0x1DE387: gatt_db_service_destroy (gatt-db.c:385)
by 0x1DE3EF: gatt_db_remove_service (gatt-db.c:519)
by 0x1D674F: discovery_op_complete (gatt-client.c:388)
by 0x1D6877: discover_primary_cb (gatt-client.c:1260)
by 0x1E220B: discovery_op_complete (gatt-helpers.c:628)
by 0x1E249B: read_by_grp_type_cb (gatt-helpers.c:730)
by 0x1D247B: disc_att_send_op (att.c:417)
by 0x1CCC17: queue_remove_all (queue.c:354)
by 0x1D47B7: disconnect_cb (att.c:635)
---
src/shared/att.c | 46 ++++++++++++++++++++++++++++++++++++++++------
1 file changed, 40 insertions(+), 6 deletions(-)
diff --git a/src/shared/att.c b/src/shared/att.c
index ed3af2920..58f23dfcb 100644
--- a/src/shared/att.c
+++ b/src/shared/att.c
@@ -84,6 +84,7 @@ struct bt_att {
struct queue *req_queue; /* Queued ATT protocol requests */
struct queue *ind_queue; /* Queued ATT protocol indications */
struct queue *write_queue; /* Queue of PDUs ready to send */
+ bool in_disc; /* Cleanup queues on disconnect_cb */
bt_att_timeout_func_t timeout_callback;
bt_att_destroy_func_t timeout_destroy;
@@ -222,8 +223,10 @@ static void destroy_att_send_op(void *data)
free(op);
}
-static void cancel_att_send_op(struct att_send_op *op)
+static void cancel_att_send_op(void *data)
{
+ struct att_send_op *op = data;
+
if (op->destroy)
op->destroy(op->user_data);
@@ -631,11 +634,6 @@ static bool disconnect_cb(struct io *io, void *user_data)
/* Dettach channel */
queue_remove(att->chans, chan);
- /* Notify request callbacks */
- queue_remove_all(att->req_queue, NULL, NULL, disc_att_send_op);
- queue_remove_all(att->ind_queue, NULL, NULL, disc_att_send_op);
- queue_remove_all(att->write_queue, NULL, NULL, disc_att_send_op);
-
if (chan->pending_req) {
disc_att_send_op(chan->pending_req);
chan->pending_req = NULL;
@@ -654,6 +652,15 @@ static bool disconnect_cb(struct io *io, void *user_data)
bt_att_ref(att);
+ att->in_disc = true;
+
+ /* Notify request callbacks */
+ queue_remove_all(att->req_queue, NULL, NULL, disc_att_send_op);
+ queue_remove_all(att->ind_queue, NULL, NULL, disc_att_send_op);
+ queue_remove_all(att->write_queue, NULL, NULL, disc_att_send_op);
+
+ att->in_disc = false;
+
queue_foreach(att->disconn_list, disconn_handler, INT_TO_PTR(err));
bt_att_unregister_all(att);
@@ -1574,6 +1581,30 @@ bool bt_att_chan_cancel(struct bt_att_chan *chan, unsigned int id)
return true;
}
+static bool bt_att_disc_cancel(struct bt_att *att, unsigned int id)
+{
+ struct att_send_op *op;
+
+ op = queue_find(att->req_queue, match_op_id, UINT_TO_PTR(id));
+ if (op)
+ goto done;
+
+ op = queue_find(att->ind_queue, match_op_id, UINT_TO_PTR(id));
+ if (op)
+ goto done;
+
+ op = queue_find(att->write_queue, match_op_id, UINT_TO_PTR(id));
+
+done:
+ if (!op)
+ return false;
+
+ /* Just cancel since disconnect_cb will be cleaning up */
+ cancel_att_send_op(op);
+
+ return true;
+}
+
bool bt_att_cancel(struct bt_att *att, unsigned int id)
{
const struct queue_entry *entry;
@@ -1591,6 +1622,9 @@ bool bt_att_cancel(struct bt_att *att, unsigned int id)
return true;
}
+ if (att->in_disc)
+ return bt_att_disc_cancel(att, id);
+
op = queue_remove_if(att->req_queue, match_op_id, UINT_TO_PTR(id));
if (op)
goto done;
--
2.25.3
