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author | David Howells <dhowells@redhat.com> | 2020-02-06 13:55:01 +0000 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-11 04:34:19 -0800 |
commit | 06748661c7dba8d8ab89ee3305e21c63218a734f (patch) | |
tree | 983e98f4527d32a78a70384549880764317dddfb | |
parent | a3623db43a3c06538591370db955d85b80657e17 (diff) | |
download | linux-rt-06748661c7dba8d8ab89ee3305e21c63218a734f.tar.gz |
rxrpc: Fix service call disconnection
[ 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>
-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 a81e64be4a24..c4c4450891e0 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -174,8 +174,6 @@ 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. @@ -228,6 +226,7 @@ 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; } |