diff options
| author | David Howells <dhowells@redhat.com> | 2020-01-30 21:50:36 +0000 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2020-02-03 10:25:30 +0000 |
| commit | 5273a191dca65a675dc0bcf3909e59c6933e2831 (patch) | |
| tree | 0944eefed2d209e9bd7ccbdebebedf367757f61a /net/rxrpc/output.c | |
| parent | 04d36d748fac349b068ef621611f454010054c58 (diff) | |
rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect
When a call is disconnected, the connection pointer from the call is
cleared to make sure it isn't used again and to prevent further attempted
transmission for the call. Unfortunately, there might be a daemon trying
to use it at the same time to transmit a packet.
Fix this by keeping call->conn set, but setting a flag on the call to
indicate disconnection instead.
Remove also the bits in the transmission functions where the conn pointer is
checked and a ref taken under spinlock as this is now redundant.
Fixes: 8d94aa381dab ("rxrpc: Calls shouldn't hold socket refs")
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'net/rxrpc/output.c')
| -rw-r--r-- | net/rxrpc/output.c | 27 |
1 files changed, 9 insertions, 18 deletions
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 935bb60fff56..bad3d2420344 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -129,7 +129,7 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_connection *conn, int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping, rxrpc_serial_t *_serial) { - struct rxrpc_connection *conn = NULL; + struct rxrpc_connection *conn; struct rxrpc_ack_buffer *pkt; struct msghdr msg; struct kvec iov[2]; @@ -139,18 +139,14 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping, int ret; u8 reason; - spin_lock_bh(&call->lock); - if (call->conn) - conn = rxrpc_get_connection_maybe(call->conn); - spin_unlock_bh(&call->lock); - if (!conn) + if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) return -ECONNRESET; pkt = kzalloc(sizeof(*pkt), GFP_KERNEL); - if (!pkt) { - rxrpc_put_connection(conn); + if (!pkt) return -ENOMEM; - } + + conn = call->conn; msg.msg_name = &call->peer->srx.transport; msg.msg_namelen = call->peer->srx.transport_len; @@ -244,7 +240,6 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping, } out: - rxrpc_put_connection(conn); kfree(pkt); return ret; } @@ -254,7 +249,7 @@ out: */ int rxrpc_send_abort_packet(struct rxrpc_call *call) { - struct rxrpc_connection *conn = NULL; + struct rxrpc_connection *conn; struct rxrpc_abort_buffer pkt; struct msghdr msg; struct kvec iov[1]; @@ -271,13 +266,11 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call) test_bit(RXRPC_CALL_TX_LAST, &call->flags)) return 0; - spin_lock_bh(&call->lock); - if (call->conn) - conn = rxrpc_get_connection_maybe(call->conn); - spin_unlock_bh(&call->lock); - if (!conn) + if (test_bit(RXRPC_CALL_DISCONNECTED, &call->flags)) return -ECONNRESET; + conn = call->conn; + msg.msg_name = &call->peer->srx.transport; msg.msg_namelen = call->peer->srx.transport_len; msg.msg_control = NULL; @@ -312,8 +305,6 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call) trace_rxrpc_tx_packet(call->debug_id, &pkt.whdr, rxrpc_tx_point_call_abort); rxrpc_tx_backoff(call, ret); - - rxrpc_put_connection(conn); return ret; } |