[PATCH 6.1 202/451] Bluetooth: hci_sync: Fix overwriting request callback

Sasha Levin
2024-03-24T23:15:26Z

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

[ Upstream commit 2615fd9a7c2507eb3be3fbe49dcec88a2f56454a ]

In a few cases the stack may generate commands as responses to events
which would happen to overwrite the sent_cmd, so this attempts to store
the request in req_skb so even if sent_cmd is replaced with a new
command the pending request will remain in stored in req_skb.

Fixes: 6a98e3836fa2 ("Bluetooth: Add helper for serialized HCI command execution")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_conn.c | 2 +-
net/bluetooth/hci_core.c | 46 ++++++++++++++++++++++----------
net/bluetooth/hci_event.c | 18 ++++++-------
net/bluetooth/hci_sync.c | 21 ++++++++++++---
5 files changed, 61 insertions(+), 27 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 2538f3b96623b..6bc6de5345261 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -549,6 +549,7 @@ struct hci_dev {
__u32 req_status;
__u32 req_result;
struct sk_buff *req_skb;
+ struct sk_buff *req_rsp;

void *smp_data;
void *smp_bredr_data;
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index f752a9f9bb9c7..bac5a369d2bef 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -2813,7 +2813,7 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason)
case HCI_EV_LE_CONN_COMPLETE:
case HCI_EV_LE_ENHANCED_CONN_COMPLETE:
case HCI_EVT_LE_CIS_ESTABLISHED:
- hci_cmd_sync_cancel(hdev, -ECANCELED);
+ hci_cmd_sync_cancel(hdev, ECANCELED);
break;
}
}
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index edf7af2e13557..e0c924df13b58 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1491,8 +1491,8 @@ static void hci_cmd_timeout(struct work_struct *work)
struct hci_dev *hdev = container_of(work, struct hci_dev,
cmd_timer.work);

- if (hdev->sent_cmd) {
- u16 opcode = hci_skb_opcode(hdev->sent_cmd);
+ if (hdev->req_skb) {
+ u16 opcode = hci_skb_opcode(hdev->req_skb);

bt_dev_err(hdev, "command 0x%4.4x tx timeout", opcode);

@@ -2792,6 +2792,7 @@ void hci_release_dev(struct hci_dev *hdev)

ida_simple_remove(&hci_index_ida, hdev->id);
kfree_skb(hdev->sent_cmd);
+ kfree_skb(hdev->req_skb);
kfree_skb(hdev->recv_event);
kfree(hdev);
}
@@ -3121,21 +3122,33 @@ int __hci_cmd_send(struct hci_dev *hdev, u16 opcode, u32 plen,
EXPORT_SYMBOL(__hci_cmd_send);

/* Get data from the previously sent command */
-void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode)
+static void *hci_cmd_data(struct sk_buff *skb, __u16 opcode)
{
struct hci_command_hdr *hdr;

- if (!hdev->sent_cmd)
+ if (!skb || skb->len < HCI_COMMAND_HDR_SIZE)
return NULL;

- hdr = (void *) hdev->sent_cmd->data;
+ hdr = (void *)skb->data;

if (hdr->opcode != cpu_to_le16(opcode))
return NULL;

- BT_DBG("%s opcode 0x%4.4x", hdev->name, opcode);
+ return skb->data + HCI_COMMAND_HDR_SIZE;
+}

- return hdev->sent_cmd->data + HCI_COMMAND_HDR_SIZE;
+/* Get data from the previously sent command */
+void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode)
+{
+ void *data;
+
+ /* Check if opcode matches last sent command */
+ data = hci_cmd_data(hdev->sent_cmd, opcode);
+ if (!data)
+ /* Check if opcode matches last request */
+ data = hci_cmd_data(hdev->req_skb, opcode);
+
+ return data;
}

/* Get data from last received event */
@@ -4031,17 +4044,19 @@ void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status,
if (!status && !hci_req_is_complete(hdev))
return;

+ skb = hdev->req_skb;
+
/* If this was the last command in a request the complete
- * callback would be found in hdev->sent_cmd instead of the
+ * callback would be found in hdev->req_skb instead of the
* command queue (hdev->cmd_q).
*/
- if (bt_cb(hdev->sent_cmd)->hci.req_flags & HCI_REQ_SKB) {
- *req_complete_skb = bt_cb(hdev->sent_cmd)->hci.req_complete_skb;
+ if (skb && bt_cb(skb)->hci.req_flags & HCI_REQ_SKB) {
+ *req_complete_skb = bt_cb(skb)->hci.req_complete_skb;
return;
}

- if (bt_cb(hdev->sent_cmd)->hci.req_complete) {
- *req_complete = bt_cb(hdev->sent_cmd)->hci.req_complete;
+ if (skb && bt_cb(skb)->hci.req_complete) {
+ *req_complete = bt_cb(skb)->hci.req_complete;
return;
}

@@ -4158,8 +4173,11 @@ static void hci_send_cmd_sync(struct hci_dev *hdev, struct sk_buff *skb)
return;
}

- if (hci_req_status_pend(hdev))
- hci_dev_set_flag(hdev, HCI_CMD_PENDING);
+ if (hci_req_status_pend(hdev) &&
+ !hci_dev_test_and_set_flag(hdev, HCI_CMD_PENDING)) {
+ kfree_skb(hdev->req_skb);
+ hdev->req_skb = skb_clone(skb, GFP_KERNEL);
+ }

atomic_dec(&hdev->cmd_cnt);
}
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 0cd093ec6486c..6b746ab9f6d21 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -4329,7 +4329,7 @@ static void hci_cmd_status_evt(struct hci_dev *hdev, void *data,
* (since for this kind of commands there will not be a command
* complete event).
*/
- if (ev->status || (hdev->sent_cmd && !hci_skb_event(hdev->sent_cmd))) {
+ if (ev->status || (hdev->req_skb && !hci_skb_event(hdev->req_skb))) {
hci_req_cmd_complete(hdev, *opcode, ev->status, req_complete,
req_complete_skb);
if (hci_dev_test_flag(hdev, HCI_CMD_PENDING)) {
@@ -7147,10 +7147,10 @@ static void hci_le_meta_evt(struct hci_dev *hdev, void *data,
bt_dev_dbg(hdev, "subevent 0x%2.2x", ev->subevent);

/* Only match event if command OGF is for LE */
- if (hdev->sent_cmd &&
- hci_opcode_ogf(hci_skb_opcode(hdev->sent_cmd)) == 0x08 &&
- hci_skb_event(hdev->sent_cmd) == ev->subevent) {
- *opcode = hci_skb_opcode(hdev->sent_cmd);
+ if (hdev->req_skb &&
+ hci_opcode_ogf(hci_skb_opcode(hdev->req_skb)) == 0x08 &&
+ hci_skb_event(hdev->req_skb) == ev->subevent) {
+ *opcode = hci_skb_opcode(hdev->req_skb);
hci_req_cmd_complete(hdev, *opcode, 0x00, req_complete,
req_complete_skb);
}
@@ -7537,10 +7537,10 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
}

/* Only match event if command OGF is not for LE */
- if (hdev->sent_cmd &&
- hci_opcode_ogf(hci_skb_opcode(hdev->sent_cmd)) != 0x08 &&
- hci_skb_event(hdev->sent_cmd) == event) {
- hci_req_cmd_complete(hdev, hci_skb_opcode(hdev->sent_cmd),
+ if (hdev->req_skb &&
+ hci_opcode_ogf(hci_skb_opcode(hdev->req_skb)) != 0x08 &&
+ hci_skb_event(hdev->req_skb) == event) {
+ hci_req_cmd_complete(hdev, hci_skb_opcode(hdev->req_skb),
status, &req_complete, &req_complete_skb);
req_evt = event;
}
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index d0029f10d9023..65b2ad34179f8 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -31,6 +31,10 @@ static void hci_cmd_sync_complete(struct hci_dev *hdev, u8 result, u16 opcode,
hdev->req_result = result;
hdev->req_status = HCI_REQ_DONE;

+ /* Free the request command so it is not used as response */
+ kfree_skb(hdev->req_skb);
+ hdev->req_skb = NULL;
+
if (skb) {
struct sock *sk = hci_skb_sk(skb);

@@ -38,7 +42,7 @@ static void hci_cmd_sync_complete(struct hci_dev *hdev, u8 result, u16 opcode,
if (sk)
sock_put(sk);

- hdev->req_skb = skb_get(skb);
+ hdev->req_rsp = skb_get(skb);
}

wake_up_interruptible(&hdev->req_wait_q);
@@ -186,8 +190,8 @@ struct sk_buff *__hci_cmd_sync_sk(struct hci_dev *hdev, u16 opcode, u32 plen,

hdev->req_status = 0;
hdev->req_result = 0;
- skb = hdev->req_skb;
- hdev->req_skb = NULL;
+ skb = hdev->req_rsp;
+ hdev->req_rsp = NULL;

bt_dev_dbg(hdev, "end: err %d", err);

@@ -4879,6 +4883,11 @@ int hci_dev_open_sync(struct hci_dev *hdev)
hdev->sent_cmd = NULL;
}

+ if (hdev->req_skb) {
+ kfree_skb(hdev->req_skb);
+ hdev->req_skb = NULL;
+ }
+
clear_bit(HCI_RUNNING, &hdev->flags);
hci_sock_dev_event(hdev, HCI_DEV_CLOSE);

@@ -5040,6 +5049,12 @@ int hci_dev_close_sync(struct hci_dev *hdev)
hdev->sent_cmd = NULL;
}

+ /* Drop last request */
+ if (hdev->req_skb) {
+ kfree_skb(hdev->req_skb);
+ hdev->req_skb = NULL;
+ }
+
clear_bit(HCI_RUNNING, &hdev->flags);
hci_sock_dev_event(hdev, HCI_DEV_CLOSE);

--
2.43.0