diff options
author | David Howells <dhowells@redhat.com> | 2020-02-06 13:55:01 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2020-02-07 11:19:38 +0100 |
commit | b39a934ec72fa2b5a74123891f25273a38378b90 (patch) | |
tree | 5379ccc45be371b09cd4ac292ff8c2b2724edb04 /net | |
parent | f798a5a0a60575f329ff29b13360bf4a14cc90d1 (diff) |
rxrpc: Fix service call disconnection
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>
Diffstat (limited to 'net')
-rw-r--r-- | net/rxrpc/conn_object.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index c0b3154f7a7e..19e141eeed17 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -171,8 +171,6 @@ 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. @@ -225,6 +223,7 @@ 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; } |