From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794591309; b=KMjvwzrbTDkTIHS0cTnhCuBHYHyEjc5OJUyQg8nfRbNnhggZemuHPLRomwPi4B+AbJY+ YfucnOYF4qL8szvTz5O5rCct7pbgGmPX7N4hkEma1jlmjRTfiCQ7pP5tQerMP+4yr+eDI /j1YhWwwX+nkGRX86MzW9op+vqqY1/OdXeDko/xiOlMwp7/zI0lPArsbpNHheu0E5SF1t be9NePWhwRml7+nCwvswuadYaBnGSeipgyqxCBWaGX3j3p9VF1yOf3kaB3M05me2kjKx4 THC4QaSCiLXvz1cLMSe3B+jafSAv7W8QtPDJnfi7Va6D5QmyoOCwlDWQm6cxcxJ07cQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591309; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=nsrvd9Ielw6Vj6MsC4xoKU4/6I3HrRm2EWgRnA8MwlY=; b=zbnHpv/Z0nSQ3yAMkNfj1GLmi9CF0COcmZLYDWfRtF3ixB88N1hGs7D05VtodRGnghnI eysyDVrmef5v+hSUzDMf+RJAjCNNZU7F2knLxR/nxgtJwQuE+z3Je1hHQoMV27jiOi4+K Q8gkKtp3KfxSppyXWp1IZHjPqmnm7j2JyeTZ+hVtJIaLVWWJbl0BvW/CsqFYOQEtxhB5a 7mnuExgUyq/fAVg5IPh2kH4thGj0BKSkPSF/p8AykAUgnU6gph1v4Um7iF279QamYY+03 QgiBg5H6vn5s04A0kopGvFAQh0sjq3N+E8IMt4zzfxeb/lnpSEWOI93i/rlENAqCOmA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Nn6Db+Vf; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AED19606B218; Fri, 13 Nov 2026 17:35:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Nn6Db+Vf Received: by smtp.kernel.org (Postfix) with ESMTPSA id 582C21F000C5; Fri, 13 Nov 2026 17:35:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591309; bh=nsrvd9Ielw6Vj6MsC4xoKU4/6I3HrRm2EWgRnA8MwlY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Nn6Db+Vfufa1rFlKpAJhgVokPHmBidTEl6GmMq+i23iey7fn65WnDMXDY7kFJ+211 NJuS10TbZPtGXJ5WBIdxn6U9F6FyR8pLYdu/LhkVSBItPqSjsIqBGJxOXxvD2Coc3/ AXkgYQz6BI3EBQYHxDGzet4Nqv1rMojaSrHOjHEs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Valentin Kindschi , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.12 422/670] Bluetooth: hci_sync: pause advertising for the scan address update Date: Fri, 13 Nov 2026 10:49:46 -0500 Message-ID: <20261113153826.040754336@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Valentin Kindschi [ Upstream commit 56ed6b127a27c418dc2daa3fd076539d8fe69c4c ] hci_active_scan_sync() programs a non-resolvable private address with LE Set Random Address on every active scan start. BLUETOOTH CORE SPECIFICATION Vol 4, Part E, 7.8.4 says the controller shall return Command Disallowed (0x0C) for that command while legacy advertising or scanning is enabled. hci_pause_addr_resolution(), called just above, only stops advertising when LL privacy is in use, so on a controller without it the command is issued while advertising is still on: Bluetooth: hci0: Opcode 0x2005 failed: -16 It does not converge either. hdev->random_addr is only set on a successful command complete, so it stays BDADDR_ANY, and the deferral added by commit c2994b008492 ("Bluetooth: hci_sync: Fix not setting Random Address when required") requires it to be set. Unlike the resolvable address a few lines above, which is reused while rpa_valid(), the non-resolvable one is regenerated and rewritten on every call, so a controller that refuses the write is asked again at the scan restart period of about 10 s, for as long as discovery keeps restarting. Observed on a BCM43455, which has no LL privacy and no extended advertising, 190 rejections in one capture, every one retrying the same address: < LE Set Random Address Address: 02:16:91:90:F1:D4 (Non-Resolvable) > Command Complete LE Set Random Address, Command Disallowed < LE Set Random Address Address: 26:90:57:96:9A:3E (Non-Resolvable) > Command Complete LE Set Random Address, Command Disallowed Pause advertising for the address update, and resume it once the update is done and before the scan is started. The pause does not outlive the function: it is taken only when nothing else holds it, and every exit resumes advertising, which also releases the pause taken by hci_pause_addr_resolution(). A failed pause returns before marking anything paused, so the error path is a no-op. The resume in the error path is no longer guarded by ll_privacy_capable(). That guard matched a pause taken only under LL privacy; the pause added here is unconditional, and hci_resume_advertising_sync() returns early when nothing was paused. One caveat this widens, raised on the previous posting. When HCI_ADVERTISING is set, hci_pause_advertising_sync() also clears HCI_DISCOVERABLE and HCI_LIMITED_DISCOVERABLE and zeroes discov_timeout, and hci_resume_advertising_sync() restores only HCI_ADVERTISING, so the discoverable state is lost. It reproduces today on an LL privacy controller through hci_pause_addr_resolution(); the unconditional pause makes it reachable without LL privacy as well. hci_suspend_sync() also pauses unconditionally, so a device that suspends loses the same state on any controller today. That asymmetry is pre-existing and is left alone here rather than folded into a scan path fix. Legacy controllers have one random address register, shared by the scanner and the advertiser. Restoring the advertiser here can reprogram it when the advertiser is non-connectable, so the scan then uses that address rather than the one generated for it. Both are non-resolvable and neither is linkable to the identity address. With privacy enabled both roles already share one resolvable address the same way. With the patch, on the same hardware: < LE Set Advertising Enable Enable: 0x00 Success < LE Set Random Address Success < LE Set Advertising Parameters Success < LE Set Advertising Enable Enable: 0x01 Success < LE Set Scan Parameters Success < LE Set Scan Enable Enable: 0x01 Success The address write is accepted, and advertising is restored before the scan is started. Over 119369 btmon records and about 12 minutes of the normal workload of that device, alternating active and passive scanning with ten outgoing connection attempts, every LE Set Random Address succeeded and there were no Command Disallowed responses of any opcode, against one per scan restart before. Patch 1 is required: without it the resume added here returns -EPERM on the controllers this fixes and leaves advertising disabled. Fixes: 3c44a431d62b ("Bluetooth: hci_sync: Resume adv with no RPA when active scan") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-5.5 btmon Signed-off-by: Valentin Kindschi Signed-off-by: Luiz Augusto von Dentz [ Valentin: Adjusted for 6.12.y: the privacy guard removed in the failed: label reads use_ll_privacy(hdev) in this tree, and the context uses test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks) instead of hci_test_quirk(). The added lines are unchanged. Requires commit 737139f4157d ("Bluetooth: hci_sync: re-enable legacy advertising on resume"). ] Signed-off-by: Valentin Kindschi Signed-off-by: Sasha Levin --- net/bluetooth/hci_sync.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c index 3856f29a301c0..e0bcb000107c5 100644 --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -6154,6 +6154,7 @@ static int hci_active_scan_sync(struct hci_dev *hdev, uint16_t interval) u8 filter_policy = 0x00; /* Default is to enable duplicates filter */ u8 filter_dup = LE_SCAN_FILTER_DUP_ENABLE; + bool paused; int err; bt_dev_dbg(hdev, ""); @@ -6177,6 +6178,12 @@ static int hci_active_scan_sync(struct hci_dev *hdev, uint16_t interval) if (err) goto failed; + /* LE Set Random Address is disallowed while advertising is enabled. */ + paused = !hdev->advertising_paused; + err = hci_pause_advertising_sync(hdev); + if (err) + goto failed; + /* All active scans will be done with either a resolvable private * address (when privacy feature has been enabled) or non-resolvable * private address. @@ -6186,6 +6193,9 @@ static int hci_active_scan_sync(struct hci_dev *hdev, uint16_t interval) if (err < 0) own_addr_type = ADDR_LE_DEV_PUBLIC; + if (paused) + hci_resume_advertising_sync(hdev); + if (hci_is_adv_monitoring(hdev) || (test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks) && hdev->discovery.result_filtering)) { @@ -6209,9 +6219,8 @@ static int hci_active_scan_sync(struct hci_dev *hdev, uint16_t interval) return err; failed: - /* Resume advertising if it was paused */ - if (use_ll_privacy(hdev)) - hci_resume_advertising_sync(hdev); + /* No-op when advertising was not paused. */ + hci_resume_advertising_sync(hdev); /* Resume passive scanning */ hci_update_passive_scan_sync(hdev); -- 2.53.0