[3.13.y.z extended stable] Patch "Bluetooth: never linger on process exit" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    Bluetooth: never linger on process exit

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 3fc84cbc5e8ec3bc1ef9633461b7b1fe4e01f598 Mon Sep 17 00:00:00 2001
From: Vladimir Davydov <vdavydov at parallels.com>
Date: Tue, 15 Jul 2014 12:25:28 +0400
Subject: 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 at parallels.com>
Signed-off-by: Marcel Holtmann <marcel at holtmann.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 net/bluetooth/l2cap_sock.c  | 3 ++-
 net/bluetooth/rfcomm/sock.c | 3 ++-
 net/bluetooth/sco.c         | 6 ++++--
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index c9e0915..eaa5ad5 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -978,7 +978,8 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 		l2cap_chan_close(chan, 0);
 		lock_sock(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);
 	}
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 3c2d3e4..a0050de 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -898,7 +898,8 @@ 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 24fa396..316dd4e 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -909,7 +909,8 @@ 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);
 	}
@@ -929,7 +930,8 @@ 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);
--
1.9.1