From: Daniel Rosenberg <drosen@google.com>
To: "Theodore Ts'o" <tytso@mit.edu>,
linux-ext4@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
Chao Yu <chao@kernel.org>,
linux-f2fs-devel@lists.sourceforge.net,
Eric Biggers <ebiggers@kernel.org>,
linux-fscrypt@vger.kernel.org,
Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>,
Jonathan Corbet <corbet@lwn.net>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
Gabriel Krisman Bertazi <krisman@collabora.com>,
kernel-team@android.com, Daniel Rosenberg <drosen@google.com>
Subject: [PATCH v3 2/9] fscrypt: Don't allow v1 policies with casefolding
Date: Fri, 17 Jan 2020 13:42:39 -0800 [thread overview]
Message-ID: <20200117214246.235591-3-drosen@google.com> (raw)
In-Reply-To: <20200117214246.235591-1-drosen@google.com>
Casefolding currently requires a derived key for computing the siphash.
This is available for v2 policies, but not v1, so we disallow it for v1.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
---
fs/crypto/policy.c | 28 ++++++++++++++++++++++++++++
fs/inode.c | 3 ++-
include/linux/fscrypt.h | 11 +++++++++++
3 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index f1cff83c151ac..2cd9a940d8f46 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -124,6 +124,12 @@ static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy,
policy->filenames_encryption_mode))
return false;
+ if (IS_CASEFOLDED(inode)) {
+ fscrypt_warn(inode,
+ "v1 policy does not support casefolded directories");
+ return false;
+ }
+
return true;
}
@@ -579,3 +585,25 @@ int fscrypt_inherit_context(struct inode *parent, struct inode *child,
return preload ? fscrypt_get_encryption_info(child): 0;
}
EXPORT_SYMBOL(fscrypt_inherit_context);
+
+int fscrypt_ioc_setflags_prepare(struct inode *inode,
+ unsigned int oldflags,
+ unsigned int flags)
+{
+ union fscrypt_policy policy;
+ int err;
+
+ /*
+ * When a directory is encrypted, the CASEFOLD flag can only be turned
+ * on if the fscrypt policy supports it.
+ */
+ if (IS_ENCRYPTED(inode) && (flags & ~oldflags & FS_CASEFOLD_FL)) {
+ err = fscrypt_get_policy(inode, &policy);
+ if (err)
+ return err;
+ if (policy.version != FSCRYPT_POLICY_V2)
+ return -EINVAL;
+ }
+
+ return 0;
+}
diff --git a/fs/inode.c b/fs/inode.c
index 96d62d97694ef..8f6267858d0c1 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -20,6 +20,7 @@
#include <linux/ratelimit.h>
#include <linux/list_lru.h>
#include <linux/iversion.h>
+#include <linux/fscrypt.h>
#include <trace/events/writeback.h>
#include "internal.h"
@@ -2252,7 +2253,7 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags,
!capable(CAP_LINUX_IMMUTABLE))
return -EPERM;
- return 0;
+ return fscrypt_ioc_setflags_prepare(inode, oldflags, flags);
}
EXPORT_SYMBOL(vfs_ioc_setflags_prepare);
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index 1dfbed855beeb..2c292f19c6b94 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -142,6 +142,10 @@ extern int fscrypt_ioctl_get_policy_ex(struct file *, void __user *);
extern int fscrypt_has_permitted_context(struct inode *, struct inode *);
extern int fscrypt_inherit_context(struct inode *, struct inode *,
void *, bool);
+extern int fscrypt_ioc_setflags_prepare(struct inode *inode,
+ unsigned int oldflags,
+ unsigned int flags);
+
/* keyring.c */
extern void fscrypt_sb_free(struct super_block *sb);
extern int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
@@ -383,6 +387,13 @@ static inline int fscrypt_inherit_context(struct inode *parent,
return -EOPNOTSUPP;
}
+static inline int fscrypt_ioc_setflags_prepare(struct inode *inode,
+ unsigned int oldflags,
+ unsigned int flags)
+{
+ return 0;
+}
+
/* keyring.c */
static inline void fscrypt_sb_free(struct super_block *sb)
{
--
2.25.0.341.g760bfbb309-goog
next prev parent reply other threads:[~2020-01-17 21:43 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-17 21:42 [PATCH v3 0/9] Support for Casefolding and Encryption Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 1/9] fscrypt: Add siphash and hash key for policy v2 Daniel Rosenberg
2020-01-17 21:42 ` Daniel Rosenberg [this message]
2020-01-17 21:42 ` [PATCH v3 3/9] fscrypt: Change format of no-key token Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 4/9] fscrypt: Only create hash key when needed Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 5/9] vfs: Fold casefolding into vfs Daniel Rosenberg
2020-01-20 1:35 ` Al Viro
2020-01-24 4:30 ` Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 6/9] f2fs: Handle casefolding with Encryption Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 7/9] ext4: Use struct super_blocks' casefold data Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 8/9] ext4: Hande casefolding with encryption Daniel Rosenberg
2020-01-17 21:42 ` [PATCH v3 9/9] ext4: Optimize match for casefolded encrypted dirs Daniel Rosenberg
2020-01-20 4:52 ` [PATCH v3 0/9] Support for Casefolding and Encryption Eric Biggers
2020-01-20 22:10 ` Eric Biggers
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