Bluetooth: never linger on process exit

commit 093facf3634da1b0c2cc7ed106f1983da901bbab upstream.

If the current process is exiting, lingering on socket close will make
it unkillable, so we should avoid it.

Reproducer:

  #include <sys/types.h>
  #include <sys/socket.h>

  #define BTPROTO_L2CAP   0
  #define BTPROTO_SCO     2
  #define BTPROTO_RFCOMM  3

  int main()
  {
          int fd;
          struct linger ling;

          fd = socket(PF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);
          //or: fd = socket(PF_BLUETOOTH, SOCK_DGRAM, BTPROTO_L2CAP);
          //or: fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO);

          ling.l_onoff = 1;
          ling.l_linger = 1000000000;
          setsockopt(fd, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling));

          return 0;
  }

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 158887a..74e59cd 100644 (file)
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -804,7 +804,8 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
                sk->sk_shutdown = SHUTDOWN_MASK;
                l2cap_chan_close(chan, 0);
 
-               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
+               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+                   !(current->flags & PF_EXITING))
                        err = bt_sock_wait_state(sk, BT_CLOSED,
                                                        sk->sk_lingertime);
        }

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 14c4864..93a8241 100644 (file)
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -901,7 +901,8 @@ static int rfcomm_sock_shutdown(struct socket *sock, int how)
                sk->sk_shutdown = SHUTDOWN_MASK;
                __rfcomm_sock_close(sk);
 
-               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
+               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+                   !(current->flags & PF_EXITING))
                        err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
        }
        release_sock(sk);

diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index a324b00..2e80aee 100644 (file)
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -774,7 +774,8 @@ static int sco_sock_shutdown(struct socket *sock, int how)
                sco_sock_clear_timer(sk);
                __sco_sock_close(sk);
 
-               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
+               if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+                   !(current->flags & PF_EXITING))
                        err = bt_sock_wait_state(sk, BT_CLOSED,
                                                        sk->sk_lingertime);
        }
@@ -794,7 +795,8 @@ static int sco_sock_release(struct socket *sock)
 
        sco_sock_close(sk);
 
-       if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime) {
+       if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime &&
+           !(current->flags & PF_EXITING)) {
                lock_sock(sk);
                err = bt_sock_wait_state(sk, BT_CLOSED, sk->sk_lingertime);
                release_sock(sk);