[PATCH v2 1/2] Bluetooth: Fix skb allocation in mgmt_remote_name() & mgmt_device_connected()
From: Radoslaw Biernacki <hidden>
Date: 2022-02-01 20:04:05
Also in:
linux-bluetooth, lkml
Subsystem:
bluetooth subsystem, the rest · Maintainers:
Marcel Holtmann, Luiz Augusto von Dentz, Linus Torvalds
From: Radoslaw Biernacki <redacted>
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 <redacted>
Signed-off-by: Marek Maslanka <redacted>
Signed-off-by: Radoslaw Biernacki <redacted>
---
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 5dd684e0b259..43ca228104ce 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c@@ -9061,12 +9061,14 @@ 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);
@@ -9785,13 +9787,11 @@ 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);
@@ -9801,10 +9801,8 @@ 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; }
--
2.35.0.rc2.247.g8bbb082509-goog