From: Mickaël Salaün Date: Tue, 22 Mar 2022 11:13:23 +0000 (+0100) Subject: certs: Explain the rationale to call panic() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4d99750106adbaecee587232f2589f65170d5ce4;p=linux.git certs: Explain the rationale to call panic() 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 --- diff --git a/certs/blacklist.c b/certs/blacklist.c index 486ce0dd8e9cb..25094ea736007 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) {