diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-01-27 08:11:44 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-01-29 18:30:56 -0500 |
| commit | f1712c73714088a7252d276a57126d56c7d37e64 (patch) | |
| tree | 962ee49daf8d1cba8403fcf03b315d4a142ec944 /net/can/af_can.h | |
| parent | dc97a89e726c4e1830320d1db8215ef77ecebae0 (diff) | |
can: Fix kernel panic at security_sock_rcv_skb
Zhang Yanmin reported crashes [1] and provided a patch adding a
synchronize_rcu() call in can_rx_unregister()
The main problem seems that the sockets themselves are not RCU
protected.
If CAN uses RCU for delivery, then sockets should be freed only after
one RCU grace period.
Recent kernels could use sock_set_flag(sk, SOCK_RCU_FREE), but let's
ease stable backports with the following fix instead.
[1]
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffff81495e25>] selinux_socket_sock_rcv_skb+0x65/0x2a0
Call Trace:
<IRQ>
[<ffffffff81485d8c>] security_sock_rcv_skb+0x4c/0x60
[<ffffffff81d55771>] sk_filter+0x41/0x210
[<ffffffff81d12913>] sock_queue_rcv_skb+0x53/0x3a0
[<ffffffff81f0a2b3>] raw_rcv+0x2a3/0x3c0
[<ffffffff81f06eab>] can_rcv_filter+0x12b/0x370
[<ffffffff81f07af9>] can_receive+0xd9/0x120
[<ffffffff81f07beb>] can_rcv+0xab/0x100
[<ffffffff81d362ac>] __netif_receive_skb_core+0xd8c/0x11f0
[<ffffffff81d36734>] __netif_receive_skb+0x24/0xb0
[<ffffffff81d37f67>] process_backlog+0x127/0x280
[<ffffffff81d36f7b>] net_rx_action+0x33b/0x4f0
[<ffffffff810c88d4>] __do_softirq+0x184/0x440
[<ffffffff81f9e86c>] do_softirq_own_stack+0x1c/0x30
<EOI>
[<ffffffff810c76fb>] do_softirq.part.18+0x3b/0x40
[<ffffffff810c8bed>] do_softirq+0x1d/0x20
[<ffffffff81d30085>] netif_rx_ni+0xe5/0x110
[<ffffffff8199cc87>] slcan_receive_buf+0x507/0x520
[<ffffffff8167ef7c>] flush_to_ldisc+0x21c/0x230
[<ffffffff810e3baf>] process_one_work+0x24f/0x670
[<ffffffff810e44ed>] worker_thread+0x9d/0x6f0
[<ffffffff810e4450>] ? rescuer_thread+0x480/0x480
[<ffffffff810ebafc>] kthread+0x12c/0x150
[<ffffffff81f9ccef>] ret_from_fork+0x3f/0x70
Reported-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/can/af_can.h')
| -rw-r--r-- | net/can/af_can.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/can/af_can.h b/net/can/af_can.h index fca0fe9fc45a..b86f5129e838 100644 --- a/net/can/af_can.h +++ b/net/can/af_can.h @@ -50,13 +50,14 @@ struct receiver { struct hlist_node list; - struct rcu_head rcu; canid_t can_id; canid_t mask; unsigned long matches; void (*func)(struct sk_buff *, void *); void *data; char *ident; + struct sock *sk; + struct rcu_head rcu; }; #define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS) |