--- /dev/null
+From 1bf4470a3939c678fb822073e9ea77a0560bc6bb Mon Sep 17 00:00:00 2001
+From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
+Date: Tue, 22 Oct 2024 12:31:08 -0400
+Subject: Bluetooth: SCO: Fix UAF on sco_sock_timeout
+
+From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
+
+commit 1bf4470a3939c678fb822073e9ea77a0560bc6bb upstream.
+
+conn->sk maybe have been unlinked/freed while waiting for sco_conn_lock
+so this checks if the conn->sk is still valid by checking if it part of
+sco_sk_list.
+
+Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
+Tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
+Closes: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
+Fixes: ba316be1b6a0 ("Bluetooth: schedule SCO timeouts with delayed_work")
+Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
+Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
+Signed-off-by: He Zhe <zhe.he@windriver.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/net/bluetooth/bluetooth.h | 1 +
+ net/bluetooth/af_bluetooth.c | 22 ++++++++++++++++++++++
+ net/bluetooth/sco.c | 18 ++++++++++++------
+ 3 files changed, 35 insertions(+), 6 deletions(-)
+
+--- a/include/net/bluetooth/bluetooth.h
++++ b/include/net/bluetooth/bluetooth.h
+@@ -314,6 +314,7 @@ int bt_sock_register(int proto, const s
+ void bt_sock_unregister(int proto);
+ void bt_sock_link(struct bt_sock_list *l, struct sock *s);
+ void bt_sock_unlink(struct bt_sock_list *l, struct sock *s);
++bool bt_sock_linked(struct bt_sock_list *l, struct sock *s);
+ int bt_sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+ int flags);
+ int bt_sock_stream_recvmsg(struct socket *sock, struct msghdr *msg,
+--- a/net/bluetooth/af_bluetooth.c
++++ b/net/bluetooth/af_bluetooth.c
+@@ -154,6 +154,28 @@ void bt_sock_unlink(struct bt_sock_list
+ }
+ EXPORT_SYMBOL(bt_sock_unlink);
+
++bool bt_sock_linked(struct bt_sock_list *l, struct sock *s)
++{
++ struct sock *sk;
++
++ if (!l || !s)
++ return false;
++
++ read_lock(&l->lock);
++
++ sk_for_each(sk, &l->head) {
++ if (s == sk) {
++ read_unlock(&l->lock);
++ return true;
++ }
++ }
++
++ read_unlock(&l->lock);
++
++ return false;
++}
++EXPORT_SYMBOL(bt_sock_linked);
++
+ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
+ {
+ BT_DBG("parent %p, sk %p", parent, sk);
+--- a/net/bluetooth/sco.c
++++ b/net/bluetooth/sco.c
+@@ -76,6 +76,16 @@ struct sco_pinfo {
+ #define SCO_CONN_TIMEOUT (HZ * 40)
+ #define SCO_DISCONN_TIMEOUT (HZ * 2)
+
++static struct sock *sco_sock_hold(struct sco_conn *conn)
++{
++ if (!conn || !bt_sock_linked(&sco_sk_list, conn->sk))
++ return NULL;
++
++ sock_hold(conn->sk);
++
++ return conn->sk;
++}
++
+ static void sco_sock_timeout(struct work_struct *work)
+ {
+ struct sco_conn *conn = container_of(work, struct sco_conn,
+@@ -87,9 +97,7 @@ static void sco_sock_timeout(struct work
+ sco_conn_unlock(conn);
+ return;
+ }
+- sk = conn->sk;
+- if (sk)
+- sock_hold(sk);
++ sk = sco_sock_hold(conn);
+ sco_conn_unlock(conn);
+
+ if (!sk)
+@@ -191,9 +199,7 @@ static void sco_conn_del(struct hci_conn
+
+ /* Kill socket */
+ sco_conn_lock(conn);
+- sk = conn->sk;
+- if (sk)
+- sock_hold(sk);
++ sk = sco_sock_hold(conn);
+ sco_conn_unlock(conn);
+
+ if (sk) {