[PATCH 3.13 080/187] Bluetooth: never linger on process exit

Kamal Mostafa
2014-09-15T22:17:14Z

From: Vladimir Davydov <vdavydov@parallels.com>

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: Kamal Mostafa <kamal@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