fscrypto: lock inode while setting encryption policy

commit 8906a8223ad4909b391c5628f7991ebceda30e52 upstream.

i_rwsem needs to be acquired while setting an encryption policy so that
concurrent calls to FS_IOC_SET_ENCRYPTION_POLICY are correctly
serialized (especially the ->get_context() + ->set_context() pair), and
so that new files cannot be created in the directory during or after the
->empty_dir() check.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Richard Weinberger <richard@nod.at>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 1fb12f9c97a6b70467700c03327f442a1a273481..789e2d6724a9deb90b080cd2e16c276357c72942 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -633,8 +633,12 @@ resizefs_out:
                if (err)
                        goto encryption_policy_out;
 
+               mutex_lock(&inode->i_mutex);
+
                err = ext4_process_policy(&policy, inode);
 
+               mutex_unlock(&inode->i_mutex);
+
                mnt_drop_write_file(filp);
 encryption_policy_out:
                return err;

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index a197215ad52bf63f4a571412ffb27b0bde9f648c..4b449d26333305a8e1483d86a3ba55e661134a54 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1535,12 +1535,19 @@ static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
        struct f2fs_encryption_policy policy;
        struct inode *inode = file_inode(filp);
+       int err;
 
        if (copy_from_user(&policy, (struct f2fs_encryption_policy __user *)arg,
                                sizeof(policy)))
                return -EFAULT;
 
-       return f2fs_process_policy(&policy, inode);
+       mutex_lock(&inode->i_mutex);
+
+       err = f2fs_process_policy(&policy, inode);
+
+       mutex_unlock(&inode->i_mutex);
+
+       return err;
 #else
        return -EOPNOTSUPP;
 #endif