[PATCH net v2 01/10] rxrpc: Fix key quota calculation for multitoken keys

[David Howells]

In the rxrpc key preparsing, every token extracted sets the proposed quota
value, but for multitoken keys, this will overwrite the previous proposed
quota, losing it.

Fix this by adding to the proposed quota instead.

Fixes: 8a7a3eb4ddbe ("KEYS: RxRPC: Use key preparsing")
Closes: https://sashiko.dev/#/patchset/20260319150150.4189381-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells at redhat.com>
cc: Marc Dionne <marc.dionne at auristor.com>
cc: Jeffrey Altman <jaltman at auristor.com>
cc: Eric Dumazet <edumazet at google.com>
cc: "David S. Miller" <davem at davemloft.net>
cc: Jakub Kicinski <kuba at kernel.org>
cc: Paolo Abeni <pabeni at redhat.com>
cc: Simon Horman <horms at kernel.org>
cc: linux-afs at lists.infradead.org
cc: netdev at vger.kernel.org
cc: stable at kernel.org
---
 net/rxrpc/key.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index 85078114b2dd..af403f0ccab5 100644
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -72,7 +72,7 @@ static int rxrpc_preparse_xdr_rxkad(struct key_preparsed_payload *prep,
 		return -EKEYREJECTED;
 
 	plen = sizeof(*token) + sizeof(*token->kad) + tktlen;
-	prep->quotalen = datalen + plen;
+	prep->quotalen += datalen + plen;
 
 	plen -= sizeof(*token);
 	token = kzalloc_obj(*token);
@@ -199,7 +199,7 @@ static int rxrpc_preparse_xdr_yfs_rxgk(struct key_preparsed_payload *prep,
 	}
 
 	plen = sizeof(*token) + sizeof(*token->rxgk) + tktlen + keylen;
-	prep->quotalen = datalen + plen;
+	prep->quotalen += datalen + plen;
 
 	plen -= sizeof(*token);
 	token = kzalloc_obj(*token);
@@ -460,6 +460,7 @@ static int rxrpc_preparse(struct key_preparsed_payload *prep)
 	memcpy(&kver, prep->data, sizeof(kver));
 	prep->data += sizeof(kver);
 	prep->datalen -= sizeof(kver);
+	prep->quotalen = 0;
 
 	_debug("KEY I/F VERSION: %u", kver);
 
@@ -497,7 +498,7 @@ static int rxrpc_preparse(struct key_preparsed_payload *prep)
 		goto error;
 
 	plen = sizeof(*token->kad) + v1->ticket_length;
-	prep->quotalen = plen + sizeof(*token);
+	prep->quotalen += plen + sizeof(*token);
 
 	ret = -ENOMEM;
 	token = kzalloc_obj(*token);