ext4: fix use-after-iput when fscrypt contexts are inconsistent
commit dd01b690f8f4b1e414f89e5a9a5326bf720d6652 upstream.
In the case where the child's encryption context was inconsistent with
its parent directory, we were using inode->i_sb and inode->i_ino after
the inode had already been iput(). Fix this by doing the iput() in the
correct places.
Note: only ext4 had this bug, not f2fs and ubifs.
Fixes: d9cdc9033181 ("ext4 crypto: enforce context consistency")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 104f8bf..c4a389a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1616,13 +1616,15 @@
!fscrypt_has_permitted_context(dir, inode)) {
int nokey = ext4_encrypted_inode(inode) &&
!fscrypt_has_encryption_key(inode);
- iput(inode);
- if (nokey)
+ if (nokey) {
+ iput(inode);
return ERR_PTR(-ENOKEY);
+ }
ext4_warning(inode->i_sb,
"Inconsistent encryption contexts: %lu/%lu",
(unsigned long) dir->i_ino,
(unsigned long) inode->i_ino);
+ iput(inode);
return ERR_PTR(-EPERM);
}
}