Fix segfault caused by integer underflow. Fix is to check that rsp->num_codecs + 3 is not bigger than size before subtracting. Crash was found by fuzzing btmon with AFL. --- monitor/packet.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/monitor/packet.c b/monitor/packet.c index 461f5e84b..1e9f9d9e4 100644 --- a/monitor/packet.c +++ b/monitor/packet.c @@ -5832,6 +5832,11 @@ static void read_local_codecs_rsp(const void *data, uint8_t size) const struct bt_hci_rsp_read_local_codecs *rsp = data; uint8_t i, num_vnd_codecs; + if (rsp->num_codecs + 3 > size) { + print_field("Invalid number of codecs."); + return; + } + print_status(rsp->status); print_field("Number of supported codecs: %d", rsp->num_codecs); -- 2.17.1