From: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx> The blacklist_init() function calls panic() for memory allocation errors. This change documents the reason why we don't return -ENODEV. Suggested-by: Paul Moore <paul@xxxxxxxxxxxxxx> [1] Requested-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> [1] Link: https://lore.kernel.org/r/YjeW2r6Wv55Du0bJ@xxxxxx [1] Reviewed-by: Paul Moore <paul@xxxxxxxxxxxxxx> Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220322111323.542184-2-mic@xxxxxxxxxxx --- Changes since v1: * Fix commit subject spelling spotted by David Woodhouse. * Reword one sentence as suggested by Paul Moore. * Add Reviewed-by Paul Moore. * Add Reviewed-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) { -- 2.35.1
