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| author | Myungho Jung <mhjungk@gmail.com> | 2019-02-02 16:56:36 -0800 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2019-02-04 15:43:46 +0100 |
| commit | e20a2e9c42c9e4002d9e338d74e7819e88d77162 (patch) | |
| tree | 6eb84aa6bbd338c29e827c6d6ff0d3f115f4c653 /net/bluetooth | |
| parent | 017a01ccfbc5a35aed83acbf2ee2735f8c3efe8a (diff) | |
| download | linux-e20a2e9c42c9e4002d9e338d74e7819e88d77162.tar.bz2 | |
Bluetooth: Fix decrementing reference count twice in releasing socket
When releasing socket, it is possible to enter hci_sock_release() and
hci_sock_dev_event(HCI_DEV_UNREG) at the same time in different thread.
The reference count of hdev should be decremented only once from one of
them but if storing hdev to local variable in hci_sock_release() before
detached from socket and setting to NULL in hci_sock_dev_event(),
hci_dev_put(hdev) is unexpectedly called twice. This is resolved by
referencing hdev from socket after bt_sock_unlink() in
hci_sock_release().
Reported-by: syzbot+fdc00003f4efff43bc5b@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/hci_sock.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 1506e1632394..d4e2a166ae17 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -831,8 +831,6 @@ static int hci_sock_release(struct socket *sock) if (!sk) return 0; - hdev = hci_pi(sk)->hdev; - switch (hci_pi(sk)->channel) { case HCI_CHANNEL_MONITOR: atomic_dec(&monitor_promisc); @@ -854,6 +852,7 @@ static int hci_sock_release(struct socket *sock) bt_sock_unlink(&hci_sk_list, sk); + hdev = hci_pi(sk)->hdev; if (hdev) { if (hci_pi(sk)->channel == HCI_CHANNEL_USER) { /* When releasing a user channel exclusive access, |