From dd01b690f8f4b1e414f89e5a9a5326bf720d6652 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Wed, 1 Feb 2017 21:07:11 -0500 Subject: [PATCH] ext4: fix use-after-iput when fscrypt contexts are inconsistent 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") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Theodore Ts'o --- fs/ext4/namei.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index bb880c326191..931da9d5d915 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1618,13 +1618,15 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi !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); } } -- 2.20.1