From ba17bb62ce415950753c19d16bb43b2bd3701158 Mon Sep 17 00:00:00 2001 From: Radoslaw Biernacki Date: Tue, 1 Feb 2022 20:10:32 +0000 Subject: [PATCH] Bluetooth: Fix skb allocation in mgmt_remote_name() & mgmt_device_connected() This patch fixes skb allocation, as lack of space for ev might push skb tail beyond its end. Also introduce eir_precalc_len() that can be used instead of magic numbers for similar eir operations on skb. Fixes: cf1bce1de7eeb ("Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_FOUND") Fixes: e96741437ef0a ("Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_CONNECTED") Signed-off-by: Angela Czubak Signed-off-by: Marek Maslanka Signed-off-by: Radoslaw Biernacki Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/eir.h | 5 +++++ net/bluetooth/mgmt.c | 18 ++++++++---------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/net/bluetooth/eir.h b/net/bluetooth/eir.h index 05e2e917fc25..e5876751f07e 100644 --- a/net/bluetooth/eir.h +++ b/net/bluetooth/eir.h @@ -15,6 +15,11 @@ u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr); u8 eir_append_local_name(struct hci_dev *hdev, u8 *eir, u8 ad_len); u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len); +static inline u16 eir_precalc_len(u8 data_len) +{ + return sizeof(u8) * 2 + data_len; +} + static inline u16 eir_append_data(u8 *eir, u16 eir_len, u8 type, u8 *data, u8 data_len) { diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c index e0d36d1e4eed..bfacf2ea692f 100644 --- a/net/bluetooth/mgmt.c +++ b/net/bluetooth/mgmt.c @@ -9085,12 +9085,14 @@ void mgmt_device_connected(struct hci_dev *hdev, struct hci_conn *conn, u16 eir_len = 0; u32 flags = 0; + /* allocate buff for LE or BR/EDR adv */ if (conn->le_adv_data_len > 0) skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_CONNECTED, - conn->le_adv_data_len); + sizeof(*ev) + conn->le_adv_data_len); else skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_CONNECTED, - 2 + name_len + 5); + sizeof(*ev) + (name ? eir_precalc_len(name_len) : 0) + + eir_precalc_len(sizeof(conn->dev_class))); ev = skb_put(skb, sizeof(*ev)); bacpy(&ev->addr.bdaddr, &conn->dst); @@ -9809,13 +9811,11 @@ void mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, { struct sk_buff *skb; struct mgmt_ev_device_found *ev; - u16 eir_len; - u32 flags; + u16 eir_len = 0; + u32 flags = 0; - if (name_len) - skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND, 2 + name_len); - else - skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND, 0); + skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND, + sizeof(*ev) + (name ? eir_precalc_len(name_len) : 0)); ev = skb_put(skb, sizeof(*ev)); bacpy(&ev->addr.bdaddr, bdaddr); @@ -9825,10 +9825,8 @@ void mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type, if (name) { eir_len = eir_append_data(ev->eir, 0, EIR_NAME_COMPLETE, name, name_len); - flags = 0; skb_put(skb, eir_len); } else { - eir_len = 0; flags = MGMT_DEV_FOUND_NAME_REQUEST_FAILED; } -- 2.11.0