From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3454E47D94B; Thu, 20 Aug 2026 17:40:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787247611; cv=none; b=N2KueLv7O9JQtAb2mIFa4cfXmUU6SrZHfvkwmdct2xXrTXtjV/vOScmKENOzTzSuqvvH5bb6iPC9zBE2uLP+lMLEKNzn0zC0QfYkNgFtS1cpL96QqhwJFMdZPb34UNY55/zSaSZM0SFdNeM0Wwv5WOFfHR55AWv+DxTBp/FrTVY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787247611; c=relaxed/simple; bh=8P3iAqNLitNj+xkCfSdqq4dqGqmeqOyGJxFksGrUfd0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=S1fCjZ6CWw6rx4iikIiuO0WMF3ALtssZnqp5Wm3dLMGCwiPvX2vHdP2A7R8f2yP4j0VheqQJQWfHfiZi6UKWuPyf9e45Y6pN2rbl56fHa07KofYrh2aafg9DiMA76k+iaSqvb13Vj4/8MiT6pZzli2H0Y78AfAkoDkyvAIBmyvk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YlKWGF6u; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="YlKWGF6u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 479071F000E9; Thu, 20 Aug 2026 17:40:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787247609; bh=DXydxtfMwo96676hMTvgeCPq9/vaXemS9aU2RXgwe6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YlKWGF6usanrt84B631/CmwQw/vli/CPgEqJUmxusC1jHZsTE8m7nBcblTBrO+Nc2 S5YuTVtjzSfshZK/ucccIQTiryuqaS/e84c0QUPmayZUNOAfx2zv+avfKpyouKBSP3 bdIKnubkS0qqf71MbiZNkB+Fpw2o+m9rgpx4n0nk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Gustavo A. R. Silva" , Luiz Augusto von Dentz , Sasha Levin Subject: [PATCH 6.6 105/166] Bluetooth: hci_conn, hci_sync: Use __counted_by() to avoid -Wfamnae warnings Date: Thu, 20 Aug 2026 16:56:04 +0200 Message-ID: <20260820145214.322610984@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145211.194104353@linuxfoundation.org> References: <20260820145211.194104353@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Gustavo A. R. Silva" [ Upstream commit c4585edf708edb5277a3cc4b8581ccb833f3307d ] Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). Also, -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. So, use the `DEFINE_FLEX()` helper for multiple on-stack definitions of a flexible structure where the size of the flexible-array member is known at compile-time, and refactor the rest of the code, accordingly. Notice that, due to the use of `__counted_by()` in `struct hci_cp_le_create_cis`, the for loop in function `hci_cs_le_create_cis()` had to be modified. Once the index `i`, through which `cp->cis[i]` is accessed, falls in the interval [0, cp->num_cis), `cp->num_cis` cannot be decremented all the way down to zero while accessing `cp->cis[]`: net/bluetooth/hci_event.c:4310: 4310 for (i = 0; cp->num_cis; cp->num_cis--, i++) { ... 4314 handle = __le16_to_cpu(cp->cis[i].cis_handle); otherwise, only half (one iteration before `cp->num_cis == i`) or half plus one (one iteration before `cp->num_cis < i`) of the items in the array will be accessed before running into an out-of-bounds issue. So, in order to avoid this, set `cp->num_cis` to zero just after the for loop. Also, make use of `aux_num_cis` variable to update `cmd->num_cis` after a `list_for_each_entry_rcu()` loop. With these changes, fix the following warnings: net/bluetooth/hci_sync.c:1239:56: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:1415:51: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:1731:51: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:6497:45: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Link: https://github.com/KSPP/linux/issues/202 Signed-off-by: Gustavo A. R. Silva Signed-off-by: Luiz Augusto von Dentz Stable-dep-of: cdc36db204ff ("Bluetooth: hci_sync: Fix advertising data UAFs") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/net/bluetooth/hci.h | 8 ++-- net/bluetooth/hci_event.c | 3 + net/bluetooth/hci_sync.c | 84 +++++++++++++++++--------------------------- 3 files changed, 40 insertions(+), 55 deletions(-) --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -1949,7 +1949,7 @@ struct hci_cp_le_set_ext_adv_data { __u8 operation; __u8 frag_pref; __u8 length; - __u8 data[]; + __u8 data[] __counted_by(length); } __packed; #define HCI_OP_LE_SET_EXT_SCAN_RSP_DATA 0x2038 @@ -1958,7 +1958,7 @@ struct hci_cp_le_set_ext_scan_rsp_data { __u8 operation; __u8 frag_pref; __u8 length; - __u8 data[]; + __u8 data[] __counted_by(length); } __packed; #define HCI_OP_LE_SET_EXT_ADV_ENABLE 0x2039 @@ -1983,7 +1983,7 @@ struct hci_cp_le_set_per_adv_data { __u8 handle; __u8 operation; __u8 length; - __u8 data[]; + __u8 data[] __counted_by(length); } __packed; #define HCI_OP_LE_SET_PER_ADV_ENABLE 0x2040 @@ -2084,7 +2084,7 @@ struct hci_cis { struct hci_cp_le_create_cis { __u8 num_cis; - struct hci_cis cis[]; + struct hci_cis cis[] __counted_by(num_cis); } __packed; #define HCI_OP_LE_REMOVE_CIG 0x2065 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -4253,7 +4253,7 @@ static void hci_cs_le_create_cis(struct hci_dev_lock(hdev); /* Remove connection if command failed */ - for (i = 0; cp->num_cis; cp->num_cis--, i++) { + for (i = 0; i < cp->num_cis; i++) { struct hci_conn *conn; u16 handle; @@ -4269,6 +4269,7 @@ static void hci_cs_le_create_cis(struct hci_conn_del(conn); } } + cp->num_cis = 0; if (pending) hci_le_create_cis_pending(hdev); --- a/net/bluetooth/hci_sync.c +++ b/net/bluetooth/hci_sync.c @@ -1297,31 +1297,27 @@ hci_set_ext_adv_params_sync(struct hci_d static int hci_set_ext_adv_data_sync(struct hci_dev *hdev, u8 instance) { - struct { - struct hci_cp_le_set_ext_adv_data cp; - u8 data[HCI_MAX_EXT_AD_LENGTH]; - } pdu; + DEFINE_FLEX(struct hci_cp_le_set_ext_adv_data, pdu, data, length, + HCI_MAX_EXT_AD_LENGTH); u8 len; struct adv_info *adv = NULL; int err; - memset(&pdu, 0, sizeof(pdu)); - if (instance) { adv = hci_find_adv_instance(hdev, instance); if (!adv || !adv->adv_data_changed) return 0; } - len = eir_create_adv_data(hdev, instance, pdu.data); + len = eir_create_adv_data(hdev, instance, pdu->data); - pdu.cp.length = len; - pdu.cp.handle = instance; - pdu.cp.operation = LE_SET_ADV_DATA_OP_COMPLETE; - pdu.cp.frag_pref = LE_SET_ADV_DATA_NO_FRAG; + pdu->length = len; + pdu->handle = instance; + pdu->operation = LE_SET_ADV_DATA_OP_COMPLETE; + pdu->frag_pref = LE_SET_ADV_DATA_NO_FRAG; err = __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_ADV_DATA, - sizeof(pdu.cp) + len, &pdu.cp, + struct_size(pdu, data, len), pdu, HCI_CMD_TIMEOUT); if (err) return err; @@ -1330,7 +1326,7 @@ static int hci_set_ext_adv_data_sync(str if (adv) { adv->adv_data_changed = false; } else { - memcpy(hdev->adv_data, pdu.data, len); + memcpy(hdev->adv_data, pdu->data, len); hdev->adv_data_len = len; } @@ -1513,31 +1509,27 @@ int hci_setup_ext_adv_instance_sync(stru static int hci_set_ext_scan_rsp_data_sync(struct hci_dev *hdev, u8 instance) { - struct { - struct hci_cp_le_set_ext_scan_rsp_data cp; - u8 data[HCI_MAX_EXT_AD_LENGTH]; - } pdu; + DEFINE_FLEX(struct hci_cp_le_set_ext_scan_rsp_data, pdu, data, length, + HCI_MAX_EXT_AD_LENGTH); u8 len; struct adv_info *adv = NULL; int err; - memset(&pdu, 0, sizeof(pdu)); - if (instance) { adv = hci_find_adv_instance(hdev, instance); if (!adv || !adv->scan_rsp_changed) return 0; } - len = eir_create_scan_rsp(hdev, instance, pdu.data); + len = eir_create_scan_rsp(hdev, instance, pdu->data); - pdu.cp.handle = instance; - pdu.cp.length = len; - pdu.cp.operation = LE_SET_ADV_DATA_OP_COMPLETE; - pdu.cp.frag_pref = LE_SET_ADV_DATA_NO_FRAG; + pdu->handle = instance; + pdu->length = len; + pdu->operation = LE_SET_ADV_DATA_OP_COMPLETE; + pdu->frag_pref = LE_SET_ADV_DATA_NO_FRAG; err = __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_EXT_SCAN_RSP_DATA, - sizeof(pdu.cp) + len, &pdu.cp, + struct_size(pdu, data, len), pdu, HCI_CMD_TIMEOUT); if (err) return err; @@ -1545,7 +1537,7 @@ static int hci_set_ext_scan_rsp_data_syn if (adv) { adv->scan_rsp_changed = false; } else { - memcpy(hdev->scan_rsp_data, pdu.data, len); + memcpy(hdev->scan_rsp_data, pdu->data, len); hdev->scan_rsp_data_len = len; } @@ -1689,14 +1681,10 @@ static int hci_set_per_adv_params_sync(s static int hci_set_per_adv_data_sync(struct hci_dev *hdev, u8 instance) { - struct { - struct hci_cp_le_set_per_adv_data cp; - u8 data[HCI_MAX_PER_AD_LENGTH]; - } pdu; + DEFINE_FLEX(struct hci_cp_le_set_per_adv_data, pdu, data, length, + HCI_MAX_PER_AD_LENGTH); u8 len; - memset(&pdu, 0, sizeof(pdu)); - if (instance) { struct adv_info *adv = hci_find_adv_instance(hdev, instance); @@ -1704,14 +1692,14 @@ static int hci_set_per_adv_data_sync(str return 0; } - len = eir_create_per_adv_data(hdev, instance, pdu.data); + len = eir_create_per_adv_data(hdev, instance, pdu->data); - pdu.cp.length = len; - pdu.cp.handle = instance; - pdu.cp.operation = LE_SET_ADV_DATA_OP_COMPLETE; + pdu->length = len; + pdu->handle = instance; + pdu->operation = LE_SET_ADV_DATA_OP_COMPLETE; return __hci_cmd_sync_status(hdev, HCI_OP_LE_SET_PER_ADV_DATA, - sizeof(pdu.cp) + len, &pdu, + struct_size(pdu, data, len), pdu, HCI_CMD_TIMEOUT); } @@ -6685,10 +6673,8 @@ done: int hci_le_create_cis_sync(struct hci_dev *hdev) { - struct { - struct hci_cp_le_create_cis cp; - struct hci_cis cis[0x1f]; - } cmd; + DEFINE_FLEX(struct hci_cp_le_create_cis, cmd, cis, num_cis, 0x1f); + size_t aux_num_cis = 0; struct hci_conn *conn; u16 timeout = 0; u8 cig = BT_ISO_QOS_CIG_UNSET; @@ -6716,8 +6702,6 @@ int hci_le_create_cis_sync(struct hci_de * remains pending. */ - memset(&cmd, 0, sizeof(cmd)); - hci_dev_lock(hdev); rcu_read_lock(); @@ -6754,7 +6738,7 @@ int hci_le_create_cis_sync(struct hci_de goto done; list_for_each_entry_rcu(conn, &hdev->conn_hash.list, list) { - struct hci_cis *cis = &cmd.cis[cmd.cp.num_cis]; + struct hci_cis *cis = &cmd->cis[aux_num_cis]; if (hci_conn_check_create_cis(conn) || conn->iso_qos.ucast.cig != cig) @@ -6764,25 +6748,25 @@ int hci_le_create_cis_sync(struct hci_de cis->acl_handle = cpu_to_le16(conn->parent->handle); cis->cis_handle = cpu_to_le16(conn->handle); timeout = conn->conn_timeout; - cmd.cp.num_cis++; + aux_num_cis++; - if (cmd.cp.num_cis >= ARRAY_SIZE(cmd.cis)) + if (aux_num_cis >= 0x1f) break; } + cmd->num_cis = aux_num_cis; done: rcu_read_unlock(); hci_dev_unlock(hdev); - if (!cmd.cp.num_cis) + if (!aux_num_cis) return 0; /* Wait for HCI_LE_CIS_Established */ return __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_CREATE_CIS, - sizeof(cmd.cp) + sizeof(cmd.cis[0]) * - cmd.cp.num_cis, &cmd, - HCI_EVT_LE_CIS_ESTABLISHED, + struct_size(cmd, cis, cmd->num_cis), + cmd, HCI_EVT_LE_CIS_ESTABLISHED, timeout, NULL); }