On 21/03/2022 19:23, Paul Moore wrote:
On Mon, Mar 21, 2022 at 1:45 PM Mickaël Salaün <mic@xxxxxxxxxxx> wrote:
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]
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220321174548.510516-2-mic@xxxxxxxxxxx
---
certs/blacklist.c | 8 ++++++++
1 file changed, 8 insertions(+)
I would suggest changing the second sentence as shown below, but
otherwise it looks good to me.
Reviewed-by: Paul Moore <paul@xxxxxxxxxxxxxx>
diff --git a/certs/blacklist.c b/certs/blacklist.c
index 486ce0dd8e9c..ac26bcf9b9a5 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -307,6 +307,14 @@ 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 the functionality doesn't load and the
"As a result if the blacklist_init() function fails for any reason the
kernel continues to execute."
Thanks, I'll fix that.
+ * kernel continues on executing. 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)
{
--
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