| Message ID | 20220526094918.482971-1-niejianglei2021@163.com |
|---|---|
| State | New |
| Headers | show |
| Series | Bluetooth: hci_conn: fix potential double free in le_scan_cleanup() | expand |
Hi, On Thu, May 26, 2022 at 4:24 AM Paolo Abeni <pabeni@redhat.com> wrote: > > On Thu, 2022-05-26 at 17:49 +0800, Jianglei Nie wrote: > > When "c == conn" is true, hci_conn_cleanup() is called. The > > hci_conn_cleanup() calls hci_dev_put() and hci_conn_put() in > > its function implementation. hci_dev_put() and hci_conn_put() > > will free the relevant resource if the reference count reaches > > zero, which may lead to a double free when hci_dev_put() and > > hci_conn_put() are called again. > > > > We should add a return to this function after hci_conn_cleanup() > > is called. > > > > Signed-off-by: Jianglei Nie <niejianglei2021@163.com> > > --- > > net/bluetooth/hci_conn.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c > > index fe803bee419a..7b3e91eb9fa3 100644 > > --- a/net/bluetooth/hci_conn.c > > +++ b/net/bluetooth/hci_conn.c > > @@ -166,6 +166,7 @@ static void le_scan_cleanup(struct work_struct *work) > > if (c == conn) { > > hci_connect_le_scan_cleanup(conn); > > hci_conn_cleanup(conn); > > + return; > > This looks not correct. At very least you should release the > hci_dev_lock. Yep, it should probably use break instead of return. > Cheers, > > Paolo >
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index fe803bee419a..7b3e91eb9fa3 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -166,6 +166,7 @@ static void le_scan_cleanup(struct work_struct *work) if (c == conn) { hci_connect_le_scan_cleanup(conn); hci_conn_cleanup(conn); + return; } hci_dev_unlock(hdev);
When "c == conn" is true, hci_conn_cleanup() is called. The hci_conn_cleanup() calls hci_dev_put() and hci_conn_put() in its function implementation. hci_dev_put() and hci_conn_put() will free the relevant resource if the reference count reaches zero, which may lead to a double free when hci_dev_put() and hci_conn_put() are called again. We should add a return to this function after hci_conn_cleanup() is called. Signed-off-by: Jianglei Nie <niejianglei2021@163.com> --- net/bluetooth/hci_conn.c | 1 + 1 file changed, 1 insertion(+)