Bluetooth: never linger on process exit
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>
Cc: stable@vger.kernel.org
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 9bb4d1b..0bc67dc 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -1112,7 +1112,8 @@
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);
}