[ Upstream commit 0cadf8534f ]
The Event_Type field in an LE Extended Advertising Report uses bits 5
and 6 for data status (e.g. truncation or fragmentation), not the PDU
type itself.
The ext_evt_type_to_legacy() function fails to mask these status bits
before evaluation. This causes valid advertisements with status bits set
(e.g. a truncated non-connectable advertisement, which ends up showing
as PDU type 0x40) to be misclassified as unknown and subsequently
dropped. This is okay for most checks which use bitwise AND on the
relevant event type bits, but it doesn't work for non-connectable types,
which are checked with '== LE_EXT_ADV_NON_CONN_IND' (that is, zero).
In terms of behaviour, first the device sends a truncated report:
> HCI Event: LE Meta Event (0x3e) plen 26
LE Extended Advertising Report (0x0d)
Entry 0
Event type: 0x0040
Data status: Incomplete, data truncated, no more to come
Address type: Random (0x01)
Address: 1D:12:46:FA:F8:6E (Non-Resolvable)
SID: 0x03
RSSI: -98 dBm (0x9e)
Data length: 0x00
Then, a few seconds later, it sends the subsequent complete report:
> HCI Event: LE Meta Event (0x3e) plen 122
LE Extended Advertising Report (0x0d)
Entry 0
Event type: 0x0000
Data status: Complete
Address type: Random (0x01)
Address: 1D:12:46:FA:F8:6E (Non-Resolvable)
SID: 0x03
RSSI: -97 dBm (0x9f)
Data length: 0x60
Service Data: Google (0xfef3)
Data[92]: ...
These devices often send multiple truncated reports per second.
This patch introduces a PDU type mask to ensure only the relevant bits
are evaluated, allowing for the correct translation of all valid
extended advertising packets.
Fixes: b2cc9761f1 ("Bluetooth: Handle extended ADV PDU types")
Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cca34a0a76