diff -drupN a/fs/crypto/policy.c b/fs/crypto/policy.c --- a/fs/crypto/policy.c 2018-08-06 17:23:04.000000000 +0300 +++ b/fs/crypto/policy.c 2022-06-12 05:28:14.000000000 +0300 @@ -10,76 +10,37 @@ #include #include -#include #include - -static int inode_has_encryption_context(struct inode *inode) -{ - if (!inode->i_sb->s_cop->get_context) - return 0; - return (inode->i_sb->s_cop->get_context(inode, NULL, 0L) > 0); -} +#include "fscrypt_private.h" /* - * check whether the policy is consistent with the encryption context - * for the inode + * check whether an encryption policy is consistent with an encryption context */ -static int is_encryption_context_consistent_with_policy(struct inode *inode, +static bool is_encryption_context_consistent_with_policy( + const struct fscrypt_context *ctx, const struct fscrypt_policy *policy) { - struct fscrypt_context ctx; - int res; - - if (!inode->i_sb->s_cop->get_context) - return 0; - - res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); - if (res != sizeof(ctx)) - return 0; - - return (memcmp(ctx.master_key_descriptor, policy->master_key_descriptor, - FS_KEY_DESCRIPTOR_SIZE) == 0 && - (ctx.flags == policy->flags) && - (ctx.contents_encryption_mode == - policy->contents_encryption_mode) && - (ctx.filenames_encryption_mode == - policy->filenames_encryption_mode)); + return memcmp(ctx->master_key_descriptor, policy->master_key_descriptor, + FS_KEY_DESCRIPTOR_SIZE) == 0 && + (ctx->flags == policy->flags) && + (ctx->contents_encryption_mode == + policy->contents_encryption_mode) && + (ctx->filenames_encryption_mode == + policy->filenames_encryption_mode); } static int create_encryption_context_from_policy(struct inode *inode, const struct fscrypt_policy *policy) { struct fscrypt_context ctx; - int res; - - if (!inode->i_sb->s_cop->set_context) - return -EOPNOTSUPP; - - if (inode->i_sb->s_cop->prepare_context) { - res = inode->i_sb->s_cop->prepare_context(inode); - if (res) - return res; - } ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; memcpy(ctx.master_key_descriptor, policy->master_key_descriptor, FS_KEY_DESCRIPTOR_SIZE); - if (!fscrypt_valid_contents_enc_mode( - policy->contents_encryption_mode)) { - printk(KERN_WARNING - "%s: Invalid contents encryption mode %d\n", __func__, - policy->contents_encryption_mode); - return -EINVAL; - } - - if (!fscrypt_valid_filenames_enc_mode( - policy->filenames_encryption_mode)) { - printk(KERN_WARNING - "%s: Invalid filenames encryption mode %d\n", __func__, - policy->filenames_encryption_mode); + if (!fscrypt_valid_enc_modes(policy->contents_encryption_mode, + policy->filenames_encryption_mode)) return -EINVAL; - } if (policy->flags & ~FS_POLICY_FLAGS_VALID) return -EINVAL; @@ -93,16 +54,20 @@ static int create_encryption_context_fro return inode->i_sb->s_cop->set_context(inode, &ctx, sizeof(ctx), NULL); } -int fscrypt_process_policy(struct file *filp, - const struct fscrypt_policy *policy) +int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg) { + struct fscrypt_policy policy; struct inode *inode = file_inode(filp); int ret; + struct fscrypt_context ctx; + + if (copy_from_user(&policy, arg, sizeof(policy))) + return -EFAULT; if (!inode_owner_or_capable(inode)) return -EACCES; - if (policy->version != 0) + if (policy.version != 0) return -EINVAL; ret = mnt_want_write_file(filp); @@ -111,22 +76,23 @@ int fscrypt_process_policy(struct file * inode_lock(inode); - if (!inode_has_encryption_context(inode)) { + ret = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx)); + if (ret == -ENODATA) { if (!S_ISDIR(inode->i_mode)) ret = -ENOTDIR; - else if (!inode->i_sb->s_cop->empty_dir) - ret = -EOPNOTSUPP; else if (!inode->i_sb->s_cop->empty_dir(inode)) ret = -ENOTEMPTY; else ret = create_encryption_context_from_policy(inode, - policy); - } else if (!is_encryption_context_consistent_with_policy(inode, - policy)) { - printk(KERN_WARNING - "%s: Policy inconsistent with encryption context\n", - __func__); - ret = -EINVAL; + &policy); + } else if (ret == sizeof(ctx) && + is_encryption_context_consistent_with_policy(&ctx, + &policy)) { + /* The file already uses the same encryption policy. */ + ret = 0; + } else if (ret >= 0 || ret == -ERANGE) { + /* The file already uses a different encryption policy. */ + ret = -EEXIST; } inode_unlock(inode); @@ -134,32 +100,38 @@ int fscrypt_process_policy(struct file * mnt_drop_write_file(filp); return ret; } -EXPORT_SYMBOL(fscrypt_process_policy); +EXPORT_SYMBOL(fscrypt_ioctl_set_policy); -int fscrypt_get_policy(struct inode *inode, struct fscrypt_policy *policy) +int fscrypt_ioctl_get_policy(struct file *filp, void __user *arg) { + struct inode *inode = file_inode(filp); struct fscrypt_context ctx; + struct fscrypt_policy policy; int res; - if (!inode->i_sb->s_cop->get_context || - !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)); + if (res < 0 && res != -ERANGE) + return res; if (res != sizeof(ctx)) - return -ENODATA; + return -EINVAL; if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1) return -EINVAL; - policy->version = 0; - policy->contents_encryption_mode = ctx.contents_encryption_mode; - policy->filenames_encryption_mode = ctx.filenames_encryption_mode; - policy->flags = ctx.flags; - memcpy(&policy->master_key_descriptor, ctx.master_key_descriptor, + policy.version = 0; + policy.contents_encryption_mode = ctx.contents_encryption_mode; + policy.filenames_encryption_mode = ctx.filenames_encryption_mode; + policy.flags = ctx.flags; + memcpy(policy.master_key_descriptor, ctx.master_key_descriptor, FS_KEY_DESCRIPTOR_SIZE); + + if (copy_to_user(arg, &policy, sizeof(policy))) + return -EFAULT; return 0; } -EXPORT_SYMBOL(fscrypt_get_policy); +EXPORT_SYMBOL(fscrypt_ioctl_get_policy); /** * fscrypt_has_permitted_context() - is a file's encryption policy permitted @@ -194,11 +166,11 @@ int fscrypt_has_permitted_context(struct 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; /* @@ -258,9 +230,9 @@ EXPORT_SYMBOL(fscrypt_has_permitted_cont * @parent: Parent inode from which the context is inherited. * @child: Child inode that inherits the context from @parent. * @fs_data: private data given by FS. - * @preload: preload child i_crypt_info + * @preload: preload child i_crypt_info if true * - * Return: Zero on success, non-zero otherwise + * Return: 0 on success, -errno on failure */ int fscrypt_inherit_context(struct inode *parent, struct inode *child, void *fs_data, bool preload) @@ -269,9 +241,6 @@ int fscrypt_inherit_context(struct inode struct fscrypt_info *ci; int res; - if (!parent->i_sb->s_cop->set_context) - return -EOPNOTSUPP; - res = fscrypt_get_encryption_info(parent); if (res < 0) return res; @@ -281,19 +250,11 @@ int fscrypt_inherit_context(struct inode return -ENOKEY; ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1; - if (fscrypt_dummy_context_enabled(parent)) { - ctx.contents_encryption_mode = FS_ENCRYPTION_MODE_AES_256_XTS; - ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS; - ctx.flags = 0; - memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE); - res = 0; - } else { - ctx.contents_encryption_mode = ci->ci_data_mode; - ctx.filenames_encryption_mode = ci->ci_filename_mode; - ctx.flags = ci->ci_flags; - memcpy(ctx.master_key_descriptor, ci->ci_master_key, - FS_KEY_DESCRIPTOR_SIZE); - } + ctx.contents_encryption_mode = ci->ci_data_mode; + ctx.filenames_encryption_mode = ci->ci_filename_mode; + ctx.flags = ci->ci_flags; + memcpy(ctx.master_key_descriptor, ci->ci_master_key, + FS_KEY_DESCRIPTOR_SIZE); get_random_bytes(ctx.nonce, FS_KEY_DERIVATION_NONCE_SIZE); res = parent->i_sb->s_cop->set_context(child, &ctx, sizeof(ctx), fs_data);