rxrpc: Downgrade the BUG() for unsupported token type in rxrpc_read()

BugLink: https://bugs.launchpad.net/bugs/1902110
[ Upstream commit 9a059cd5ca7d9c5c4ca5a6e755cf72f230176b6a ]

If rxrpc_read() (which allows KEYCTL_READ to read a key), sees a token of a
type it doesn't recognise, it can BUG in a couple of places, which is
unnecessary as it can easily get back to userspace.

Fix this to print an error message instead.

Fixes: 99455153d067 ("RxRPC: Parse security index 5 keys (Kerberos 5)")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Ian May <ian.may@canonical.com>

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index d77e89766406aa321da2fbad509d994e07de9fe6..32f46edcf7c67b5db34551b2758bc648142b45cb 100644 (file)
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -1108,7 +1108,8 @@ static long rxrpc_read(const struct key *key,
                        break;
 
                default: /* we have a ticket we can't encode */
-                       BUG();
+                       pr_err("Unsupported key token type (%u)\n",
+                              token->security_index);
                        continue;
                }
 
@@ -1224,7 +1225,6 @@ static long rxrpc_read(const struct key *key,
                        break;
 
                default:
-                       BUG();
                        break;
                }