From: Eric Biggers <ebiggers@kernel.org>
To: linux-fscrypt@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org
Subject: [PATCH 2/3] fscrypt: improve fscrypt_destroy_keyring() documentation
Date: Mon, 13 Mar 2023 15:12:30 -0700 [thread overview]
Message-ID: <20230313221231.272498-3-ebiggers@kernel.org> (raw)
In-Reply-To: <20230313221231.272498-1-ebiggers@kernel.org>
From: Eric Biggers <ebiggers@google.com>
Document that it must be called after all potentially-encrypted inodes
have been evicted.
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
fs/crypto/keyring.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c
index 78086f8dbda52..bb15709ac9a40 100644
--- a/fs/crypto/keyring.c
+++ b/fs/crypto/keyring.c
@@ -207,10 +207,11 @@ static int allocate_filesystem_keyring(struct super_block *sb)
* Release all encryption keys that have been added to the filesystem, along
* with the keyring that contains them.
*
- * This is called at unmount time. The filesystem's underlying block device(s)
- * are still available at this time; this is important because after user file
- * accesses have been allowed, this function may need to evict keys from the
- * keyslots of an inline crypto engine, which requires the block device(s).
+ * This is called at unmount time, after all potentially-encrypted inodes have
+ * been evicted. The filesystem's underlying block device(s) are still
+ * available at this time; this is important because after user file accesses
+ * have been allowed, this function may need to evict keys from the keyslots of
+ * an inline crypto engine, which requires the block device(s).
*/
void fscrypt_destroy_keyring(struct super_block *sb)
{
@@ -227,12 +228,12 @@ void fscrypt_destroy_keyring(struct super_block *sb)
hlist_for_each_entry_safe(mk, tmp, bucket, mk_node) {
/*
- * Since all inodes were already evicted, every key
- * remaining in the keyring should have an empty inode
- * list, and should only still be in the keyring due to
- * the single active ref associated with ->mk_secret.
- * There should be no structural refs beyond the one
- * associated with the active ref.
+ * Since all potentially-encrypted inodes were already
+ * evicted, every key remaining in the keyring should
+ * have an empty inode list, and should only still be in
+ * the keyring due to the single active ref associated
+ * with ->mk_secret. There should be no structural refs
+ * beyond the one associated with the active ref.
*/
WARN_ON(refcount_read(&mk->mk_active_refs) != 1);
WARN_ON(refcount_read(&mk->mk_struct_refs) != 1);
--
2.39.2
next prev parent reply other threads:[~2023-03-13 22:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-13 22:12 [PATCH 0/3] Fix crash with fscrypt + Landlock Eric Biggers
2023-03-13 22:12 ` [PATCH 1/3] fscrypt: destroy keyring after security_sb_delete() Eric Biggers
2023-03-14 9:28 ` Christian Brauner
2023-03-13 22:12 ` Eric Biggers [this message]
2023-03-13 22:12 ` [PATCH 3/3] fscrypt: check for NULL keyring in fscrypt_put_master_key_activeref() Eric Biggers
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