[BlueZ,6/6] gatt: Fix double free and freed memory dereference

Commit Message

Ildar Kamaletdinov April 1, 2022, 12:16 p.m. UTC

If device is no longer exists or not paired when notifications send it
is possible to get double free and dereference of already freed memory.

To avoid this we need to recheck the state of device after sending
notification.

Found by Linux Verification Center (linuxtesting.org) with the SVACE
static analysis tool.
---
 src/gatt-database.c | 4 ++++
 1 file changed, 4 insertions(+)

Patch

diff --git a/src/gatt-database.c b/src/gatt-database.c
index d6c94058c..d32f616a9 100644
--- a/src/gatt-database.c
+++ b/src/gatt-database.c
@@ -3877,6 +3877,10 @@  void btd_gatt_database_server_connected(struct btd_gatt_database *database,
 
 	send_notification_to_device(state, state->pending);
 
+	state = find_device_state(database, &bdaddr, bdaddr_type);
+	if (!state || !state->pending)
+		return;
+
 	free(state->pending->value);
 	free(state->pending);
 	state->pending = NULL;