From b33f5741bb187db8ff32e8f5b96def77cc94dfca Mon Sep 17 00:00:00 2001 From: Alok Tiwari Date: Wed, 8 Apr 2026 13:12:34 +0100 Subject: rxrpc: Fix use of wrong skb when comparing queued RESP challenge serial In rxrpc_post_response(), the code should be comparing the challenge serial number from the cached response before deciding to switch to a newer response, but looks at the newer packet private data instead, rendering the comparison always false. Fix this by switching to look at the older packet. Fix further[1] to substitute the new packet in place of the old one if newer and also to release whichever we don't use. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Signed-off-by: Alok Tiwari Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Marc Dionne cc: Simon Horman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://sashiko.dev/#/patchset/20260319150150.4189381-1-dhowells%40redhat.com [1] Link: https://patch.msgid.link/20260408121252.2249051-7-dhowells@redhat.com Signed-off-by: Jakub Kicinski --- net/rxrpc/conn_event.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/rxrpc') diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c index 98ad9b51ca2c..c50cbfc5a313 100644 --- a/net/rxrpc/conn_event.c +++ b/net/rxrpc/conn_event.c @@ -557,11 +557,11 @@ void rxrpc_post_response(struct rxrpc_connection *conn, struct sk_buff *skb) spin_lock_irq(&local->lock); old = conn->tx_response; if (old) { - struct rxrpc_skb_priv *osp = rxrpc_skb(skb); + struct rxrpc_skb_priv *osp = rxrpc_skb(old); /* Always go with the response to the most recent challenge. */ if (after(sp->resp.challenge_serial, osp->resp.challenge_serial)) - conn->tx_response = old; + conn->tx_response = skb; else old = skb; } else { @@ -569,4 +569,5 @@ void rxrpc_post_response(struct rxrpc_connection *conn, struct sk_buff *skb) } spin_unlock_irq(&local->lock); rxrpc_poke_conn(conn, rxrpc_conn_get_poke_response); + rxrpc_free_skb(old, rxrpc_skb_put_old_response); } -- cgit v1.2.3