diff options
| author | Eric Biggers <ebiggers@google.com> | 2023-03-13 15:12:29 -0700 |
|---|---|---|
| committer | Eric Biggers <ebiggers@google.com> | 2023-03-14 10:30:30 -0700 |
| commit | ccb820dc7d2236b1af0d54ae038a27b5b6d5ae5a (patch) | |
| tree | c31e6fba690d9cf7d956293b2858461a2a0c432c /fs/super.c | |
| parent | fe15c26ee26efa11741a7b632e9f23b01aca4cc6 (diff) | |
fscrypt: destroy keyring after security_sb_delete()
fscrypt_destroy_keyring() must be called after all potentially-encrypted
inodes were evicted; otherwise it cannot safely destroy the keyring.
Since inodes that are in-use by the Landlock LSM don't get evicted until
security_sb_delete(), this means that fscrypt_destroy_keyring() must be
called *after* security_sb_delete().
This fixes a WARN_ON followed by a NULL dereference, only possible if
Landlock was being used on encrypted files.
Fixes: d7e7b9af104c ("fscrypt: stop using keyrings subsystem for fscrypt_master_key")
Cc: stable@vger.kernel.org
Reported-by: syzbot+93e495f6a4f748827c88@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/00000000000044651705f6ca1e30@google.com
Reviewed-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230313221231.272498-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/fs/super.c b/fs/super.c index 84332d5cb817..04bc62ab7dfe 100644 --- a/fs/super.c +++ b/fs/super.c @@ -475,13 +475,22 @@ void generic_shutdown_super(struct super_block *sb) cgroup_writeback_umount(); - /* evict all inodes with zero refcount */ + /* Evict all inodes with zero refcount. */ evict_inodes(sb); - /* only nonzero refcount inodes can have marks */ + + /* + * Clean up and evict any inodes that still have references due + * to fsnotify or the security policy. + */ fsnotify_sb_delete(sb); - fscrypt_destroy_keyring(sb); security_sb_delete(sb); + /* + * Now that all potentially-encrypted inodes have been evicted, + * the fscrypt keyring can be destroyed. + */ + fscrypt_destroy_keyring(sb); + if (sb->s_dio_done_wq) { destroy_workqueue(sb->s_dio_done_wq); sb->s_dio_done_wq = NULL; |