Commit d2ae4e91 authored Sep 27, 2020 by David Howells

rxrpc: Don't leak the service-side session key to userspace

Don't let someone reading a service-side rxrpc-type key get access to the
session key that was exchanged with the client. The server application
will, at some point, need to be able to read the information in the ticket,
but this probably shouldn't include the key material.

Signed-off-by: David Howells <dhowells@redhat.com>

parent 12da59fc

include/keys/rxrpc-type.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -36,6 +36,7 @@ struct rxkad_key {
		*/
		struct rxrpc_key_token {
		u16 security_index; /* RxRPC header security index */
		bool no_leak_key; /* Don't copy the key to userspace */
		struct rxrpc_key_token next; / the next token in the list */
		union {
		struct rxkad_key *kad;

net/rxrpc/key.c

+6 −2

Original line number	Diff line number	Diff line
		@@ -579,6 +579,7 @@ static long rxrpc_read(const struct key *key,
		case RXRPC_SECURITY_RXKAD:
		toksize += 8 * 4; /* viceid, kvno, key*2, begin,
		* end, primary, tktlen */
		if (!token->no_leak_key)
		toksize += RND(token->kad->ticket_len);
		break;

		@@ -654,6 +655,9 @@ static long rxrpc_read(const struct key *key,
		ENCODE(token->kad->start);
		ENCODE(token->kad->expiry);
		ENCODE(token->kad->primary_flag);
		if (token->no_leak_key)
		ENCODE(0);
		else
		ENCODE_DATA(token->kad->ticket_len, token->kad->ticket);
		break;