6.4-stable review patch. If anyone has any objections, please let me know.
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From: Pauli Virtanen pav@iki.fi
[ Upstream commit 3344d318337d9dca928fd448e966557ec5063f85 ]
Not calling hci_(dis)connect_cfm before deleting conn referred to by a socket generally results to use-after-free.
When cleaning up SCO connections when the parent ACL is deleted too early, use hci_conn_failed to do the connection cleanup properly.
We also need to clean up ISO connections in a similar situation when connecting has started but LE Create CIS is not yet sent, so do it too here.
Fixes: ca1fd42e7dbf ("Bluetooth: Fix potential double free caused by hci_conn_unlink") Reported-by: syzbot+cf54c1da6574b6c1b049@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-bluetooth/00000000000013b93805fbbadc50@google.... Signed-off-by: Pauli Virtanen pav@iki.fi Signed-off-by: Luiz Augusto von Dentz luiz.von.dentz@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/bluetooth/hci_conn.c | 32 ++++++++++++++++++++++++-------- 1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c index 4f31340c2c932..eb2802ef34bfe 100644 --- a/net/bluetooth/hci_conn.c +++ b/net/bluetooth/hci_conn.c @@ -1040,6 +1040,29 @@ struct hci_conn *hci_conn_add(struct hci_dev *hdev, int type, bdaddr_t *dst, return conn; }
+static void hci_conn_cleanup_child(struct hci_conn *conn, u8 reason) +{ + if (!reason) + reason = HCI_ERROR_REMOTE_USER_TERM; + + /* Due to race, SCO/ISO conn might be not established yet at this point, + * and nothing else will clean it up. In other cases it is done via HCI + * events. + */ + switch (conn->type) { + case SCO_LINK: + case ESCO_LINK: + if (HCI_CONN_HANDLE_UNSET(conn->handle)) + hci_conn_failed(conn, reason); + break; + case ISO_LINK: + if (conn->state != BT_CONNECTED && + !test_bit(HCI_CONN_CREATE_CIS, &conn->flags)) + hci_conn_failed(conn, reason); + break; + } +} + static void hci_conn_unlink(struct hci_conn *conn) { struct hci_dev *hdev = conn->hdev; @@ -1062,14 +1085,7 @@ static void hci_conn_unlink(struct hci_conn *conn) if (!test_bit(HCI_UP, &hdev->flags)) continue;
- /* Due to race, SCO connection might be not established - * yet at this point. Delete it now, otherwise it is - * possible for it to be stuck and can't be deleted. - */ - if ((child->type == SCO_LINK || - child->type == ESCO_LINK) && - HCI_CONN_HANDLE_UNSET(child->handle)) - hci_conn_del(child); + hci_conn_cleanup_child(child, conn->abort_reason); }
return;