summary refs log tree commit diff
path: root/net/core
diff options
context:
space:
mode:
authorCraig Gallek <kraig@google.com>2015-06-30 12:49:32 -0400
committerDavid S. Miller <davem@davemloft.net>2015-06-30 10:00:26 -0700
commitb922622ec6efad1f28ad13053fd17e744614f77b (patch)
treeb3a97f008aa16266e56134bfeca40c446b55f386 /net/core
parent7f4ef975e96ff1a050d4e496c59bbd33e28028ed (diff)
downloadlinux-b922622ec6efad1f28ad13053fd17e744614f77b.tar.gz
sock_diag: don't broadcast kernel sockets
Kernel sockets do not hold a reference for the network namespace to
which they point.  Socket destruction broadcasting relies on the
network namespace and will cause the splat below when a kernel socket
is destroyed.

This fix simply ignores kernel sockets when they are destroyed.

Reported as:
general protection fault: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 1 PID: 9130 Comm: kworker/1:1 Not tainted 4.1.0-gelk-debug+ #1
Workqueue: sock_diag_events sock_diag_broadcast_destroy_work
Stack:
 ffff8800b9c586c0 ffff8800b9c586c0 ffff8800ac4692c0 ffff8800936d4a90
 ffff8800352efd38 ffffffff8469a93e ffff8800352efd98 ffffffffc09b9b90
 ffff8800352efd78 ffff8800ac4692c0 ffff8800b9c586c0 ffff8800831b6ab8
Call Trace:
 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10
 [<ffffffffc09b9b90>] ? inet_diag_handler_get_info+0x110/0x1fb [inet_diag]
 [<ffffffff845c868d>] netlink_broadcast+0x1d/0x20
 [<ffffffff8469a93e>] ? mutex_unlock+0xe/0x10
 [<ffffffff845b2bf5>] sock_diag_broadcast_destroy_work+0xd5/0x160
 [<ffffffff8408ea97>] process_one_work+0x147/0x420
 [<ffffffff8408f0f9>] worker_thread+0x69/0x470
 [<ffffffff8409fda3>] ? preempt_count_sub+0xa3/0xf0
 [<ffffffff8408f090>] ? rescuer_thread+0x320/0x320
 [<ffffffff84093cd7>] kthread+0x107/0x120
 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0
 [<ffffffff8469d31f>] ret_from_fork+0x3f/0x70
 [<ffffffff84093bd0>] ? kthread_create_on_node+0x1b0/0x1b0

Tested:
  Using a debug kernel while 'ss -E' is running:
  ip netns add test-ns
  ip netns delete test-ns

Fixes: eb4cb008529c sock_diag: define destruction multicast groups
Fixes: 26abe14379f8 net: Modify sk_alloc to not reference count the
  netns of kernel sockets.
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>

Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/sock.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index e4be66fb3bd5..08f16db46070 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1454,7 +1454,7 @@ void sk_destruct(struct sock *sk)
 
 static void __sk_free(struct sock *sk)
 {
-	if (unlikely(sock_diag_has_destroy_listeners(sk)))
+	if (unlikely(sock_diag_has_destroy_listeners(sk) && sk->sk_net_refcnt))
 		sock_diag_broadcast_destroy(sk);
 	else
 		sk_destruct(sk);