^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * This contains encryption functions for per-file encryption.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2015, Google, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Copyright (C) 2015, Motorola Mobility
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Written by Michael Halcrow, 2014.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Filename encryption additions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Uday Savagaonkar, 2014
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * Encryption policy handling additions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * Ildar Muslukhov, 2014
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * Add fscrypt_pullback_bio_page()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Jaegeuk Kim, 2015.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * This has not yet undergone a rigorous security audit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * The usage of AES-XTS should conform to recommendations in NIST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * Special Publication 800-38E and IEEE P1619/D16.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/mempool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/scatterlist.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/ratelimit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <crypto/skcipher.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include "fscrypt_private.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static unsigned int num_prealloc_crypto_pages = 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) module_param(num_prealloc_crypto_pages, uint, 0444);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) MODULE_PARM_DESC(num_prealloc_crypto_pages,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) "Number of crypto pages to preallocate");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static mempool_t *fscrypt_bounce_page_pool = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) static struct workqueue_struct *fscrypt_read_workqueue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) static DEFINE_MUTEX(fscrypt_init_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) struct kmem_cache *fscrypt_info_cachep;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) void fscrypt_enqueue_decrypt_work(struct work_struct *work)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) queue_work(fscrypt_read_workqueue, work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) EXPORT_SYMBOL(fscrypt_enqueue_decrypt_work);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return mempool_alloc(fscrypt_bounce_page_pool, gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * fscrypt_free_bounce_page() - free a ciphertext bounce page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * @bounce_page: the bounce page to free, or NULL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * Free a bounce page that was allocated by fscrypt_encrypt_pagecache_blocks(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * or by fscrypt_alloc_bounce_page() directly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) void fscrypt_free_bounce_page(struct page *bounce_page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) if (!bounce_page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) set_page_private(bounce_page, (unsigned long)NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) ClearPagePrivate(bounce_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) mempool_free(bounce_page, fscrypt_bounce_page_pool);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) EXPORT_SYMBOL(fscrypt_free_bounce_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * Generate the IV for the given logical block number within the given file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * For filenames encryption, lblk_num == 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) * Keep this in sync with fscrypt_limit_io_blocks(). fscrypt_limit_io_blocks()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * needs to know about any IV generation methods where the low bits of IV don't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * simply contain the lblk_num (e.g., IV_INO_LBLK_32).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) void fscrypt_generate_iv(union fscrypt_iv *iv, u64 lblk_num,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) const struct fscrypt_info *ci)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) u8 flags = fscrypt_policy_flags(&ci->ci_policy);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) memset(iv, 0, ci->ci_mode->ivsize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) WARN_ON_ONCE(lblk_num > U32_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) WARN_ON_ONCE(ci->ci_inode->i_ino > U32_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) lblk_num |= (u64)ci->ci_inode->i_ino << 32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) } else if (flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) WARN_ON_ONCE(lblk_num > U32_MAX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) lblk_num = (u32)(ci->ci_hashed_ino + lblk_num);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) } else if (flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) memcpy(iv->nonce, ci->ci_nonce, FSCRYPT_FILE_NONCE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) iv->lblk_num = cpu_to_le64(lblk_num);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* Encrypt or decrypt a single filesystem block of file contents */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) int fscrypt_crypt_block(const struct inode *inode, fscrypt_direction_t rw,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) u64 lblk_num, struct page *src_page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) struct page *dest_page, unsigned int len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) unsigned int offs, gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) union fscrypt_iv iv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) struct skcipher_request *req = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) DECLARE_CRYPTO_WAIT(wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) struct scatterlist dst, src;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) struct fscrypt_info *ci = inode->i_crypt_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) struct crypto_skcipher *tfm = ci->ci_enc_key.tfm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) int res = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) if (WARN_ON_ONCE(len <= 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (WARN_ON_ONCE(len % FS_CRYPTO_BLOCK_SIZE != 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) fscrypt_generate_iv(&iv, lblk_num, ci);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) req = skcipher_request_alloc(tfm, gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (!req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) skcipher_request_set_callback(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) req, CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) crypto_req_done, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) sg_init_table(&dst, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) sg_set_page(&dst, dest_page, len, offs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) sg_init_table(&src, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) sg_set_page(&src, src_page, len, offs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) skcipher_request_set_crypt(req, &src, &dst, len, &iv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (rw == FS_DECRYPT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) res = crypto_wait_req(crypto_skcipher_decrypt(req), &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) res = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) skcipher_request_free(req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) if (res) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) fscrypt_err(inode, "%scryption failed for block %llu: %d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) (rw == FS_DECRYPT ? "De" : "En"), lblk_num, res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * fscrypt_encrypt_pagecache_blocks() - Encrypt filesystem blocks from a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) * pagecache page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) * @page: The locked pagecache page containing the block(s) to encrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) * @len: Total size of the block(s) to encrypt. Must be a nonzero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) * multiple of the filesystem's block size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) * @offs: Byte offset within @page of the first block to encrypt. Must be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) * a multiple of the filesystem's block size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * @gfp_flags: Memory allocation flags. See details below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) * A new bounce page is allocated, and the specified block(s) are encrypted into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * it. In the bounce page, the ciphertext block(s) will be located at the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * offsets at which the plaintext block(s) were located in the source page; any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) * other parts of the bounce page will be left uninitialized. However, normally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * blocksize == PAGE_SIZE and the whole page is encrypted at once.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * This is for use by the filesystem's ->writepages() method.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * The bounce page allocation is mempool-backed, so it will always succeed when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * @gfp_flags includes __GFP_DIRECT_RECLAIM, e.g. when it's GFP_NOFS. However,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * only the first page of each bio can be allocated this way. To prevent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * deadlocks, for any additional pages a mask like GFP_NOWAIT must be used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * Return: the new encrypted bounce page on success; an ERR_PTR() on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) unsigned int len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) unsigned int offs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) const struct inode *inode = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) const unsigned int blockbits = inode->i_blkbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) const unsigned int blocksize = 1 << blockbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) struct page *ciphertext_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) (offs >> blockbits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) if (WARN_ON_ONCE(!PageLocked(page)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) ciphertext_page = fscrypt_alloc_bounce_page(gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) if (!ciphertext_page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) err = fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) page, ciphertext_page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) blocksize, i, gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) fscrypt_free_bounce_page(ciphertext_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) SetPagePrivate(ciphertext_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) set_page_private(ciphertext_page, (unsigned long)page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) return ciphertext_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) EXPORT_SYMBOL(fscrypt_encrypt_pagecache_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) * fscrypt_encrypt_block_inplace() - Encrypt a filesystem block in-place
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) * @inode: The inode to which this block belongs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * @page: The page containing the block to encrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * @len: Size of block to encrypt. Doesn't need to be a multiple of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * fs block size, but must be a multiple of FS_CRYPTO_BLOCK_SIZE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) * @offs: Byte offset within @page at which the block to encrypt begins
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * number of the block within the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * @gfp_flags: Memory allocation flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * Encrypt a possibly-compressed filesystem block that is located in an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) * arbitrary page, not necessarily in the original pagecache page. The @inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) * and @lblk_num must be specified, as they can't be determined from @page.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) * Return: 0 on success; -errno on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) int fscrypt_encrypt_block_inplace(const struct inode *inode, struct page *page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) unsigned int len, unsigned int offs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) u64 lblk_num, gfp_t gfp_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) return fscrypt_crypt_block(inode, FS_ENCRYPT, lblk_num, page, page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) len, offs, gfp_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) EXPORT_SYMBOL(fscrypt_encrypt_block_inplace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) * fscrypt_decrypt_pagecache_blocks() - Decrypt filesystem blocks in a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) * pagecache page
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) * @page: The locked pagecache page containing the block(s) to decrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) * @len: Total size of the block(s) to decrypt. Must be a nonzero
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) * multiple of the filesystem's block size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) * @offs: Byte offset within @page of the first block to decrypt. Must be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) * a multiple of the filesystem's block size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) * The specified block(s) are decrypted in-place within the pagecache page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) * which must still be locked and not uptodate. Normally, blocksize ==
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) * PAGE_SIZE and the whole page is decrypted at once.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) * This is for use by the filesystem's ->readpages() method.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * Return: 0 on success; -errno on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) int fscrypt_decrypt_pagecache_blocks(struct page *page, unsigned int len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) unsigned int offs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) const struct inode *inode = page->mapping->host;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) const unsigned int blockbits = inode->i_blkbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) const unsigned int blocksize = 1 << blockbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) u64 lblk_num = ((u64)page->index << (PAGE_SHIFT - blockbits)) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) (offs >> blockbits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (WARN_ON_ONCE(!PageLocked(page)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) if (WARN_ON_ONCE(len <= 0 || !IS_ALIGNED(len | offs, blocksize)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) for (i = offs; i < offs + len; i += blocksize, lblk_num++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) err = fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) page, blocksize, i, GFP_NOFS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) EXPORT_SYMBOL(fscrypt_decrypt_pagecache_blocks);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * fscrypt_decrypt_block_inplace() - Decrypt a filesystem block in-place
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * @inode: The inode to which this block belongs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * @page: The page containing the block to decrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * @len: Size of block to decrypt. Doesn't need to be a multiple of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * fs block size, but must be a multiple of FS_CRYPTO_BLOCK_SIZE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * @offs: Byte offset within @page at which the block to decrypt begins
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * @lblk_num: Filesystem logical block number of the block, i.e. the 0-based
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * number of the block within the file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * Decrypt a possibly-compressed filesystem block that is located in an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) * arbitrary page, not necessarily in the original pagecache page. The @inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) * and @lblk_num must be specified, as they can't be determined from @page.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) * Return: 0 on success; -errno on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) unsigned int len, unsigned int offs,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) u64 lblk_num)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) return fscrypt_crypt_block(inode, FS_DECRYPT, lblk_num, page, page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) len, offs, GFP_NOFS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) EXPORT_SYMBOL(fscrypt_decrypt_block_inplace);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) * fscrypt_initialize() - allocate major buffers for fs encryption.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * @cop_flags: fscrypt operations flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * We only call this when we start accessing encrypted files, since it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * results in memory getting allocated that wouldn't otherwise be used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * Return: 0 on success; -errno on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) int fscrypt_initialize(unsigned int cop_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) /* No need to allocate a bounce page pool if this FS won't use it. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) if (cop_flags & FS_CFLG_OWN_PAGES)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) mutex_lock(&fscrypt_init_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) if (fscrypt_bounce_page_pool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) fscrypt_bounce_page_pool =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) mempool_create_page_pool(num_prealloc_crypto_pages, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (!fscrypt_bounce_page_pool)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) mutex_unlock(&fscrypt_init_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) void fscrypt_msg(const struct inode *inode, const char *level,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) const char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) DEFAULT_RATELIMIT_BURST);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) struct va_format vaf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) va_list args;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) if (!__ratelimit(&rs))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) va_start(args, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) vaf.fmt = fmt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) vaf.va = &args;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) if (inode && inode->i_ino)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) printk("%sfscrypt (%s, inode %lu): %pV\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) level, inode->i_sb->s_id, inode->i_ino, &vaf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) else if (inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) printk("%sfscrypt (%s): %pV\n", level, inode->i_sb->s_id, &vaf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) printk("%sfscrypt: %pV\n", level, &vaf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) va_end(args);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) * fscrypt_init() - Set up for fs encryption.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) * Return: 0 on success; -errno on failure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) static int __init fscrypt_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) int err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * Use an unbound workqueue to allow bios to be decrypted in parallel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * even when they happen to complete on the same CPU. This sacrifices
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * locality, but it's worthwhile since decryption is CPU-intensive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * Also use a high-priority workqueue to prioritize decryption work,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * which blocks reads from completing, over regular application tasks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) fscrypt_read_workqueue = alloc_workqueue("fscrypt_read_queue",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) WQ_UNBOUND | WQ_HIGHPRI,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) num_online_cpus());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) if (!fscrypt_read_workqueue)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) fscrypt_info_cachep = KMEM_CACHE(fscrypt_info, SLAB_RECLAIM_ACCOUNT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) if (!fscrypt_info_cachep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) goto fail_free_queue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) err = fscrypt_init_keyring();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) goto fail_free_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) fail_free_info:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) kmem_cache_destroy(fscrypt_info_cachep);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) fail_free_queue:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) destroy_workqueue(fscrypt_read_workqueue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) late_initcall(fscrypt_init)
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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