From ea8ae2516ac43028a01c40b58ffa80d3b0afb802 Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Wed, 17 Dec 2014 18:18:08 +0100 Subject: [PATCH] Bluetooth: Fix bug with filter in service discovery optimization MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The optimization for filtering out extended inquiry results, advertising reports or scan response data based on provided UUID list has a logic bug. In case no match is found in the advertising data, the scan response is ignored and not checked against the filter. This will lead to events being filtered wrongly. Change the code to actually only drop the events when the scan response data is not present. If it is present, it needs to be checked against the provided filter. The patch is a bit more complex than it needs to be. That is because it also fixes this compiler warning that some gcc versions produce. CC net/bluetooth/mgmt.o net/bluetooth/mgmt.c: In function ‘mgmt_device_found’: net/bluetooth/mgmt.c:7028:7: warning: ‘match’ may be used uninitialized in this function [-Wmaybe-uninitialized] bool match; ^ It seems that gcc can not clearly figure out the context of the match variable. So just change the branches for the extended inquiry response and advertising data around so that it is clear. Reported-by: Geert Uytterhoeven Signed-off-by: Marcel Holtmann Signed-off-by: Johan Hedberg --- net/bluetooth/mgmt.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index 06c2e652e4b6..693ce8bcd06e 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -7081,13 +7081,15 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, * kept and checking possible scan response data * will be skipped. */ - if (hdev->discovery.uuid_count > 0) { + if (hdev->discovery.uuid_count > 0) match = eir_has_uuids(eir, eir_len, hdev->discovery.uuid_count, hdev->discovery.uuids); - if (!match) - return; - } + else + match = true; + + if (!match && !scan_rsp_len) + return; /* Copy EIR or advertising data into event */ memcpy(ev->eir, eir, eir_len); @@ -7096,8 +7098,10 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, * provided, results with empty EIR or advertising data * should be dropped since they do not match any UUID. */ - if (hdev->discovery.uuid_count > 0) + if (hdev->discovery.uuid_count > 0 && !scan_rsp_len) return; + + match = false; } if (dev_class && !eir_has_data_type(ev->eir, eir_len, EIR_CLASS_OF_DEV)) -- 2.20.1