ext4 crypto: move context consistency check to ext4_file_open()
In the case where the per-file key for the directory is cached, but
root does not have access to the key needed to derive the per-file key
for the files in the directory, we allow the lookup to succeed, so
that lstat(2) and unlink(2) can suceed. However, if a program tries
to open the file, it will get an ENOKEY error.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1126436..474f1a4 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -350,6 +350,7 @@
struct super_block *sb = inode->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
struct vfsmount *mnt = filp->f_path.mnt;
+ struct inode *dir = filp->f_path.dentry->d_parent->d_inode;
struct path path;
char buf[64], *cp;
int ret;
@@ -393,6 +394,14 @@
if (ext4_encryption_info(inode) == NULL)
return -ENOKEY;
}
+ if (ext4_encrypted_inode(dir) &&
+ !ext4_is_child_context_consistent_with_parent(dir, inode)) {
+ ext4_warning(inode->i_sb,
+ "Inconsistent encryption contexts: %lu/%lu\n",
+ (unsigned long) dir->i_ino,
+ (unsigned long) inode->i_ino);
+ return -EPERM;
+ }
/*
* Set up the jbd2_inode if we are opening the inode for
* writing and the journal is present
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5de8483..48e4b89 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1603,11 +1603,15 @@
return ERR_PTR(-EFSCORRUPTED);
}
if (!IS_ERR(inode) && ext4_encrypted_inode(dir) &&
- (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
- S_ISLNK(inode->i_mode)) &&
+ (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
!ext4_is_child_context_consistent_with_parent(dir,
inode)) {
+ int nokey = ext4_encrypted_inode(inode) &&
+ !ext4_encryption_info(inode);
+
iput(inode);
+ if (nokey)
+ return ERR_PTR(-ENOKEY);
ext4_warning(inode->i_sb,
"Inconsistent encryption contexts: %lu/%lu\n",
(unsigned long) dir->i_ino,