From 4d99750106adbaecee587232f2589f65170d5ce4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= Date: Tue, 22 Mar 2022 12:13:23 +0100 Subject: [PATCH] certs: Explain the rationale to call panic() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The blacklist_init() function calls panic() for memory allocation errors. This change documents the reason why we don't return -ENODEV. Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@digikod.net Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@iki.fi Suggested-by: Paul Moore Reviewed-by: Paul Moore Reviewed-by: Jarkko Sakkinen Signed-off-by: Mickaël Salaün Signed-off-by: Jarkko Sakkinen --- certs/blacklist.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/certs/blacklist.c b/certs/blacklist.c index 486ce0dd8e9c..25094ea73600 100644 --- a/certs/blacklist.c +++ b/certs/blacklist.c @@ -307,6 +307,15 @@ static int restrict_link_for_blacklist(struct key *dest_keyring, /* * Initialise the blacklist + * + * The blacklist_init() function is registered as an initcall via + * device_initcall(). As a result if the blacklist_init() function fails for + * any reason the kernel continues to execute. While cleanly returning -ENODEV + * could be acceptable for some non-critical kernel parts, if the blacklist + * keyring fails to load it defeats the certificate/key based deny list for + * signed modules. If a critical piece of security functionality that users + * expect to be present fails to initialize, panic()ing is likely the right + * thing to do. */ static int __init blacklist_init(void) {