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| author | Myungho Jung <mhjungk@gmail.com> | 2019-02-02 16:56:36 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-27 14:17:57 +0900 |
| commit | 4d18023ade55906b1e1f4983f59082f747499778 (patch) | |
| tree | 8586d5086d2e8c84919e2d8afd6e5caa74f9a943 /net | |
| parent | 572ae5c7646b36b06d8431682ebfca66229b2ff4 (diff) | |
| download | talos-obmc-linux-4d18023ade55906b1e1f4983f59082f747499778.tar.gz talos-obmc-linux-4d18023ade55906b1e1f4983f59082f747499778.zip | |
Bluetooth: Fix decrementing reference count twice in releasing socket
commit e20a2e9c42c9e4002d9e338d74e7819e88d77162 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
| -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, |
