diff mbox series

[v1,6/9] certs: Fix blacklist flag type confusion

Message ID 20201120180426.922572-7-mic@digikod.net (mailing list archive)
State New
Headers show
Series Enable root to update the blacklist keyring | expand

Commit Message

Mickaël Salaün Nov. 20, 2020, 6:04 p.m. UTC
From: Mickaël Salaün <mic@linux.microsoft.com>

KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() nor
key_alloc(), which only takes KEY_ALLOC_* flags.  KEY_FLAG_KEEP has the
same value as KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only
key_create_or_update() uses it.  LSMs using the key_alloc hook don't
check such flag.

KEY_FLAG_KEEP is then ignored but fortunately (again) the root user
cannot write to the blacklist keyring, then it is not possible to remove
a key/hash from it.

Remove KEY_FLAG_KEEP from the call to keyring_alloc() and set the
keyring flags with it.

This should not fix a bug with the current implementation but it is
required for the next commit to allow to add new hashes to the blacklist
without the possibility to remove them.

Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
 certs/blacklist.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/certs/blacklist.c b/certs/blacklist.c
index 0d2c959e9422..d1e2f69d91c2 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -224,11 +224,11 @@  static int __init blacklist_init(void)
 			      (KEY_POS_ALL & ~KEY_POS_SETATTR) |
-			      KEY_FLAG_KEEP,
 			      NULL, NULL);
 	if (IS_ERR(blacklist_keyring))
 		panic("Can't allocate system blacklist keyring\n");
+	set_bit(KEY_FLAG_KEEP, &blacklist_keyring->flags);
 	for (bl = blacklist_hashes; *bl; bl++)
 		if (mark_raw_hash_blacklisted(*bl) < 0)