From: Douya Le Date: Wed, 8 Apr 2026 12:12:38 +0000 (+0100) Subject: rxrpc: Only put the call ref if one was acquired X-Git-Tag: v7.0~27^2~17^2~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6331f1b24a3e85465f6454e003a3e6c22005a5c5;p=thirdparty%2Fkernel%2Flinux.git rxrpc: Only put the call ref if one was acquired rxrpc_input_packet_on_conn() can process a to-client packet after the current client call on the channel has already been torn down. In that case chan->call is NULL, rxrpc_try_get_call() returns NULL and there is no reference to drop. The client-side implicit-end error path does not account for that and unconditionally calls rxrpc_put_call(). This turns a protocol error path into a kernel crash instead of rejecting the packet. Only drop the call reference if one was actually acquired. Keep the existing protocol error handling unchanged. Fixes: 5e6ef4f1017c ("rxrpc: Make the I/O thread take over the call and local processor work") Reported-by: Yifan Wu Reported-by: Juefei Pu Signed-off-by: Douya Le Co-developed-by: Yuan Tan Signed-off-by: Yuan Tan Suggested-by: Xin Liu Signed-off-by: Ao Zhou Signed-off-by: David Howells cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260408121252.2249051-11-dhowells@redhat.com Signed-off-by: Jakub Kicinski --- diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c index e939ecf417c4b..6979569319252 100644 --- a/net/rxrpc/io_thread.c +++ b/net/rxrpc/io_thread.c @@ -419,7 +419,8 @@ static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn, if (sp->hdr.callNumber > chan->call_id) { if (rxrpc_to_client(sp)) { - rxrpc_put_call(call, rxrpc_call_put_input); + if (call) + rxrpc_put_call(call, rxrpc_call_put_input); return rxrpc_protocol_error(skb, rxrpc_eproto_unexpected_implicit_end); }