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authorDavid Howells <dhowells@redhat.com>2020-01-30 21:50:36 +0000
committerDavid Howells <dhowells@redhat.com>2020-02-03 10:25:30 +0000
commit5273a191dca65a675dc0bcf3909e59c6933e2831 (patch)
tree0944eefed2d209e9bd7ccbdebebedf367757f61a /net/rxrpc/output.c
parentrxrpc: Fix missing active use pinning of rxrpc_local object (diff)
downloadlinux-dev-5273a191dca65a675dc0bcf3909e59c6933e2831.tar.xz
linux-dev-5273a191dca65a675dc0bcf3909e59c6933e2831.zip
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 '')
-rw-r--r--net/rxrpc/output.c27
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;
}