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authorLinus Torvalds <torvalds@linux-foundation.org>2017-11-14 22:35:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-14 22:35:15 +0300
commit32190f0afbf4f1c0a9142e5a886a078ee0b794fd (patch)
tree865f5cd7effacf40c02e7cda5c31fef8a0624c89 /fs/crypto
parent37dc79565c4b7e735f190eaa6ed5bb6eb3d3968a (diff)
parenta0b3bc855374c50b5ea85273553485af48caf2f7 (diff)
downloadlinux-32190f0afbf4f1c0a9142e5a886a078ee0b794fd.tar.xz
Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt
Pull fscrypt updates from Ted Ts'o: "Lots of cleanups, mostly courtesy by Eric Biggers" * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: lock mutex before checking for bounce page pool fscrypt: add a documentation file for filesystem-level encryption ext4: switch to fscrypt_prepare_setattr() ext4: switch to fscrypt_prepare_lookup() ext4: switch to fscrypt_prepare_rename() ext4: switch to fscrypt_prepare_link() ext4: switch to fscrypt_file_open() fscrypt: new helper function - fscrypt_prepare_setattr() fscrypt: new helper function - fscrypt_prepare_lookup() fscrypt: new helper function - fscrypt_prepare_rename() fscrypt: new helper function - fscrypt_prepare_link() fscrypt: new helper function - fscrypt_file_open() fscrypt: new helper function - fscrypt_require_key() fscrypt: remove unneeded empty fscrypt_operations structs fscrypt: remove ->is_encrypted() fscrypt: switch from ->is_encrypted() to IS_ENCRYPTED() fs, fscrypt: add an S_ENCRYPTED inode flag fscrypt: clean up include file mess
Diffstat (limited to 'fs/crypto')
-rw-r--r--fs/crypto/Makefile2
-rw-r--r--fs/crypto/crypto.c9
-rw-r--r--fs/crypto/fname.c3
-rw-r--r--fs/crypto/fscrypt_private.h3
-rw-r--r--fs/crypto/hooks.c112
-rw-r--r--fs/crypto/keyinfo.c2
-rw-r--r--fs/crypto/policy.c6
7 files changed, 123 insertions, 14 deletions
diff --git a/fs/crypto/Makefile b/fs/crypto/Makefile
index 9f6607f17b53..cb496989a6b6 100644
--- a/fs/crypto/Makefile
+++ b/fs/crypto/Makefile
@@ -1,4 +1,4 @@
obj-$(CONFIG_FS_ENCRYPTION) += fscrypto.o
-fscrypto-y := crypto.o fname.o policy.o keyinfo.o
+fscrypto-y := crypto.o fname.o hooks.o keyinfo.o policy.o
fscrypto-$(CONFIG_BLOCK) += bio.o
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index 80a3cada53de..732a786cce9d 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -320,7 +320,7 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
return -ECHILD;
dir = dget_parent(dentry);
- if (!d_inode(dir)->i_sb->s_cop->is_encrypted(d_inode(dir))) {
+ if (!IS_ENCRYPTED(d_inode(dir))) {
dput(dir);
return 0;
}
@@ -390,11 +390,8 @@ int fscrypt_initialize(unsigned int cop_flags)
{
int i, res = -ENOMEM;
- /*
- * No need to allocate a bounce page pool if there already is one or
- * this FS won't use it.
- */
- if (cop_flags & FS_CFLG_OWN_PAGES || fscrypt_bounce_page_pool)
+ /* No need to allocate a bounce page pool if this FS won't use it. */
+ if (cop_flags & FS_CFLG_OWN_PAGES)
return 0;
mutex_lock(&fscrypt_init_mutex);
diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index 0b94cd2b3222..305541bcd108 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -359,8 +359,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
memset(fname, 0, sizeof(struct fscrypt_name));
fname->usr_fname = iname;
- if (!dir->i_sb->s_cop->is_encrypted(dir) ||
- fscrypt_is_dot_dotdot(iname)) {
+ if (!IS_ENCRYPTED(dir) || fscrypt_is_dot_dotdot(iname)) {
fname->disk_name.name = (unsigned char *)iname->name;
fname->disk_name.len = iname->len;
return 0;
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h
index e54e602b473f..c0b4f5597e1a 100644
--- a/fs/crypto/fscrypt_private.h
+++ b/fs/crypto/fscrypt_private.h
@@ -12,7 +12,8 @@
#ifndef _FSCRYPT_PRIVATE_H
#define _FSCRYPT_PRIVATE_H
-#include <linux/fscrypt_supp.h>
+#define __FS_HAS_ENCRYPTION 1
+#include <linux/fscrypt.h>
#include <crypto/hash.h>
/* Encryption parameters */
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
new file mode 100644
index 000000000000..9f5fb2eb9cf7
--- /dev/null
+++ b/fs/crypto/hooks.c
@@ -0,0 +1,112 @@
+/*
+ * fs/crypto/hooks.c
+ *
+ * Encryption hooks for higher-level filesystem operations.
+ */
+
+#include <linux/ratelimit.h>
+#include "fscrypt_private.h"
+
+/**
+ * fscrypt_file_open - prepare to open a possibly-encrypted regular file
+ * @inode: the inode being opened
+ * @filp: the struct file being set up
+ *
+ * Currently, an encrypted regular file can only be opened if its encryption key
+ * is available; access to the raw encrypted contents is not supported.
+ * Therefore, we first set up the inode's encryption key (if not already done)
+ * and return an error if it's unavailable.
+ *
+ * We also verify that if the parent directory (from the path via which the file
+ * is being opened) is encrypted, then the inode being opened uses the same
+ * encryption policy. This is needed as part of the enforcement that all files
+ * in an encrypted directory tree use the same encryption policy, as a
+ * protection against certain types of offline attacks. Note that this check is
+ * needed even when opening an *unencrypted* file, since it's forbidden to have
+ * an unencrypted file in an encrypted directory.
+ *
+ * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code
+ */
+int fscrypt_file_open(struct inode *inode, struct file *filp)
+{
+ int err;
+ struct dentry *dir;
+
+ err = fscrypt_require_key(inode);
+ if (err)
+ return err;
+
+ dir = dget_parent(file_dentry(filp));
+ if (IS_ENCRYPTED(d_inode(dir)) &&
+ !fscrypt_has_permitted_context(d_inode(dir), inode)) {
+ pr_warn_ratelimited("fscrypt: inconsistent encryption contexts: %lu/%lu",
+ d_inode(dir)->i_ino, inode->i_ino);
+ err = -EPERM;
+ }
+ dput(dir);
+ return err;
+}
+EXPORT_SYMBOL_GPL(fscrypt_file_open);
+
+int __fscrypt_prepare_link(struct inode *inode, struct inode *dir)
+{
+ int err;
+
+ err = fscrypt_require_key(dir);
+ if (err)
+ return err;
+
+ if (!fscrypt_has_permitted_context(dir, inode))
+ return -EPERM;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__fscrypt_prepare_link);
+
+int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ int err;
+
+ err = fscrypt_require_key(old_dir);
+ if (err)
+ return err;
+
+ err = fscrypt_require_key(new_dir);
+ if (err)
+ return err;
+
+ if (old_dir != new_dir) {
+ if (IS_ENCRYPTED(new_dir) &&
+ !fscrypt_has_permitted_context(new_dir,
+ d_inode(old_dentry)))
+ return -EPERM;
+
+ if ((flags & RENAME_EXCHANGE) &&
+ IS_ENCRYPTED(old_dir) &&
+ !fscrypt_has_permitted_context(old_dir,
+ d_inode(new_dentry)))
+ return -EPERM;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__fscrypt_prepare_rename);
+
+int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry)
+{
+ int err = fscrypt_get_encryption_info(dir);
+
+ if (err)
+ return err;
+
+ if (fscrypt_has_encryption_key(dir)) {
+ spin_lock(&dentry->d_lock);
+ dentry->d_flags |= DCACHE_ENCRYPTED_WITH_KEY;
+ spin_unlock(&dentry->d_lock);
+ }
+
+ d_set_d_op(dentry, &fscrypt_d_ops);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__fscrypt_prepare_lookup);
diff --git a/fs/crypto/keyinfo.c b/fs/crypto/keyinfo.c
index 4486b3eecc27..5e6e846f5a24 100644
--- a/fs/crypto/keyinfo.c
+++ b/fs/crypto/keyinfo.c
@@ -259,7 +259,7 @@ int fscrypt_get_encryption_info(struct inode *inode)
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
if (res < 0) {
if (!fscrypt_dummy_context_enabled(inode) ||
- inode->i_sb->s_cop->is_encrypted(inode))
+ IS_ENCRYPTED(inode))
return res;
/* Fake up a context for an unencrypted directory */
memset(&ctx, 0, sizeof(ctx));
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index a120649beeca..c6d431a5cce9 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -110,7 +110,7 @@ int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg)
struct fscrypt_policy policy;
int res;
- if (!inode->i_sb->s_cop->is_encrypted(inode))
+ if (!IS_ENCRYPTED(inode))
return -ENODATA;
res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));
@@ -167,11 +167,11 @@ int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
return 1;
/* No restrictions if the parent directory is unencrypted */
- if (!cops->is_encrypted(parent))
+ if (!IS_ENCRYPTED(parent))
return 1;
/* Encrypted directories must not contain unencrypted files */
- if (!cops->is_encrypted(child))
+ if (!IS_ENCRYPTED(child))
return 0;
/*