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authorTheodore Ts'o <tytso@mit.edu>2016-02-08 00:54:26 -0500
committerTheodore Ts'o <tytso@mit.edu>2016-02-08 00:54:26 -0500
commitff978b09f973db0d0597704eba350a994d7729e6 (patch)
tree75f1066159641b2e1cc9891a7d6ccd5cb3b29826 /fs/ext4
parent28b4c263961c47da84ed8b5be0b5116bad1133eb (diff)
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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>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/file.c9
-rw-r--r--fs/ext4/namei.c8
2 files changed, 15 insertions, 2 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1126436dada1..474f1a4d2ca8 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -350,6 +350,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
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 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
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 5de8483f0062..48e4b8907826 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1603,11 +1603,15 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
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,