From: David Howells dhowells@redhat.com
[ Upstream commit b39a934ec72fa2b5a74123891f25273a38378b90 ]
The recent patch that substituted a flag on an rxrpc_call for the connection pointer being NULL as an indication that a call was disconnected puts the set_bit in the wrong place for service calls. This is only a problem if a call is implicitly terminated by a new call coming in on the same connection channel instead of a terminating ACK packet.
In such a case, rxrpc_input_implicit_end_call() calls __rxrpc_disconnect_call(), which is now (incorrectly) setting the disconnection bit, meaning that when rxrpc_release_call() is later called, it doesn't call rxrpc_disconnect_call() and so the call isn't removed from the peer's error distribution list and the list gets corrupted.
KASAN finds the issue as an access after release on a call, but the position at which it occurs is confusing as it appears to be related to a different call (the call site is where the latter call is being removed from the error distribution list and either the next or pprev pointer points to a previously released call).
Fix this by moving the setting of the flag from __rxrpc_disconnect_call() to rxrpc_disconnect_call() in the same place that the connection pointer was being cleared.
Fixes: 5273a191dca6 ("rxrpc: Fix NULL pointer deref due to call->conn being cleared on disconnect") Signed-off-by: David Howells dhowells@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/rxrpc/conn_object.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index 13b29e491de91..af02328205979 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -163,8 +163,6 @@ void __rxrpc_disconnect_call(struct rxrpc_connection *conn,
_enter("%d,%x", conn->debug_id, call->cid);
- set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); - if (rcu_access_pointer(chan->call) == call) { /* Save the result of the call so that we can repeat it if necessary * through the channel, whilst disposing of the actual call record. @@ -209,6 +207,7 @@ void rxrpc_disconnect_call(struct rxrpc_call *call) __rxrpc_disconnect_call(conn, call); spin_unlock(&conn->channel_lock);
+ set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); conn->idle_timestamp = jiffies; }