From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This fixes the following race:
cpu1 cpu2
==== ====
sock_ioctl
sock_do_ioctl
hci_sock_ioctl
hci_rx_work hci_dev_cmd
hci_event_packet hci_req_sync
req_complete_skb __hci_req_sync
hci_req_sync_complete
If hci_rx_work executes before __hci_req_sync releases req_skb, everything
is normal, otherwise it will result in double free of req_skb.
This replaces the usage of hci_req_sync with hci_cmd_sync_status.
Fixes: 45d355a926ab ("Bluetooth: Fix memory leak in hci_req_sync_complete()")
Reported-and-tested-by: syzbot+35ebc808442df6420eae@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=35ebc808442df6420eae
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
include/net/bluetooth/hci_sync.h | 2 +
net/bluetooth/hci_core.c | 72 ++++++++------------------------
net/bluetooth/hci_sync.c | 13 ++++++
3 files changed, 33 insertions(+), 54 deletions(-)
diff --git a/include/net/bluetooth/hci_sync.h b/include/net/bluetooth/hci_sync.h
index b49057bbdf23..20168732f20e 100644
--- a/include/net/bluetooth/hci_sync.h
+++ b/include/net/bluetooth/hci_sync.h
@@ -38,6 +38,8 @@ int __hci_cmd_sync_status(struct hci_dev *hdev, u16 opcode, u32 plen,
int __hci_cmd_sync_status_sk(struct hci_dev *hdev, u16 opcode, u32 plen,
const void *param, u8 event, u32 timeout,
struct sock *sk);
+int hci_cmd_sync_status(struct hci_dev *hdev, u16 opcode, u32 plen,
+ const void *param, u32 timeout);
void hci_cmd_sync_init(struct hci_dev *hdev);
void hci_cmd_sync_clear(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index d541cbb991eb..144e85ebfbdb 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -63,50 +63,6 @@ DEFINE_MUTEX(hci_cb_list_lock);
/* HCI ID Numbering */
static DEFINE_IDA(hci_index_ida);
-static int hci_scan_req(struct hci_request *req, unsigned long opt)
-{
- __u8 scan = opt;
-
- BT_DBG("%s %x", req->hdev->name, scan);
-
- /* Inquiry and Page scans */
- hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
- return 0;
-}
-
-static int hci_auth_req(struct hci_request *req, unsigned long opt)
-{
- __u8 auth = opt;
-
- BT_DBG("%s %x", req->hdev->name, auth);
-
- /* Authentication */
- hci_req_add(req, HCI_OP_WRITE_AUTH_ENABLE, 1, &auth);
- return 0;
-}
-
-static int hci_encrypt_req(struct hci_request *req, unsigned long opt)
-{
- __u8 encrypt = opt;
-
- BT_DBG("%s %x", req->hdev->name, encrypt);
-
- /* Encryption */
- hci_req_add(req, HCI_OP_WRITE_ENCRYPT_MODE, 1, &encrypt);
- return 0;
-}
-
-static int hci_linkpol_req(struct hci_request *req, unsigned long opt)
-{
- __le16 policy = cpu_to_le16(opt);
-
- BT_DBG("%s %x", req->hdev->name, policy);
-
- /* Default link policy */
- hci_req_add(req, HCI_OP_WRITE_DEF_LINK_POLICY, 2, &policy);
- return 0;
-}
-
/* Get HCI device by index.
* Device is held on return. */
struct hci_dev *hci_dev_get(int index)
@@ -735,6 +691,7 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
{
struct hci_dev *hdev;
struct hci_dev_req dr;
+ __le16 policy;
int err = 0;
if (copy_from_user(&dr, arg, sizeof(dr)))
@@ -761,8 +718,8 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
switch (cmd) {
case HCISETAUTH:
- err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt,
- HCI_INIT_TIMEOUT, NULL);
+ err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_AUTH_ENABLE,
+ 1, &dr.dev_opt, HCI_CMD_TIMEOUT);
break;
case HCISETENCRYPT:
@@ -773,19 +730,23 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
if (!test_bit(HCI_AUTH, &hdev->flags)) {
/* Auth must be enabled first */
- err = hci_req_sync(hdev, hci_auth_req, dr.dev_opt,
- HCI_INIT_TIMEOUT, NULL);
+ err = __hci_cmd_sync_status(hdev,
+ HCI_OP_WRITE_AUTH_ENABLE,
+ 1, &dr.dev_opt,
+ HCI_CMD_TIMEOUT);
if (err)
break;
}
- err = hci_req_sync(hdev, hci_encrypt_req, dr.dev_opt,
- HCI_INIT_TIMEOUT, NULL);
+ err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_ENCRYPT_MODE,
+ 1, &dr.dev_opt,
+ HCI_CMD_TIMEOUT);
break;
case HCISETSCAN:
- err = hci_req_sync(hdev, hci_scan_req, dr.dev_opt,
- HCI_INIT_TIMEOUT, NULL);
+ err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_SCAN_ENABLE,
+ 1, &dr.dev_opt,
+ HCI_CMD_TIMEOUT);
/* Ensure that the connectable and discoverable states
* get correctly modified as this was a non-mgmt change.
@@ -795,8 +756,11 @@ int hci_dev_cmd(unsigned int cmd, void __user *arg)
break;
case HCISETLINKPOL:
- err = hci_req_sync(hdev, hci_linkpol_req, dr.dev_opt,
- HCI_INIT_TIMEOUT, NULL);
+ policy = cpu_to_le16(dr.dev_opt);
+
+ err = __hci_cmd_sync_status(hdev, HCI_OP_WRITE_DEF_LINK_POLICY,
+ 2, &policy,
+ HCI_CMD_TIMEOUT);
break;
case HCISETLINKMODE:
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index eff648853ae1..ccad43f10415 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -280,6 +280,19 @@ int __hci_cmd_sync_status(struct hci_dev *hdev, u16 opcode, u32 plen,
}
EXPORT_SYMBOL(__hci_cmd_sync_status);
+int hci_cmd_sync_status(struct hci_dev *hdev, u16 opcode, u32 plen,
+ const void *param, u32 timeout)
+{
+ int err;
+
+ hci_req_sync_lock(hdev);
+ err = __hci_cmd_sync_status(hdev, opcode, plen, param, timeout);
+ hci_req_sync_unlock(hdev);
+
+ return err;
+}
+EXPORT_SYMBOL(hci_cmd_sync_status);
+
static void hci_cmd_sync_work(struct work_struct *work)
{
struct hci_dev *hdev = container_of(work, struct hci_dev, cmd_sync_work);
--
2.45.2
