^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * fs/ext4/verity.c: fs-verity support for ext4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright 2019 Google LLC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Implementation of fsverity_operations for ext4.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * ext4 stores the verity metadata (Merkle tree and fsverity_descriptor) past
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * the end of the file, starting at the first 64K boundary beyond i_size. This
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * approach works because (a) verity files are readonly, and (b) pages fully
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * beyond i_size aren't visible to userspace but can be read/written internally
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * by ext4 with only some relatively small changes to ext4. This approach
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * avoids having to depend on the EA_INODE feature and on rearchitecturing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * ext4's xattr support to support paging multi-gigabyte xattrs into memory, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * to support encrypting xattrs. Note that the verity metadata *must* be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * encrypted when the file is, since it contains hashes of the plaintext data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * Using a 64K boundary rather than a 4K one keeps things ready for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * architectures with 64K pages, and it doesn't necessarily waste space on-disk
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) * since there can be a hole between i_size and the start of the Merkle tree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/quotaops.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include "ext4.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include "ext4_extents.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) #include "ext4_jbd2.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) static inline loff_t ext4_verity_metadata_pos(const struct inode *inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) return round_up(inode->i_size, 65536);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * Read some verity metadata from the inode. __vfs_read() can't be used because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * we need to read beyond i_size.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static int pagecache_read(struct inode *inode, void *buf, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) loff_t pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) while (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) size_t n = min_t(size_t, count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) PAGE_SIZE - offset_in_page(pos));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) void *addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) page = read_mapping_page(inode->i_mapping, pos >> PAGE_SHIFT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) if (IS_ERR(page))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) return PTR_ERR(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) addr = kmap_atomic(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) memcpy(buf, addr + offset_in_page(pos), n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) kunmap_atomic(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) buf += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) pos += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) count -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) * Write some verity metadata to the inode for FS_IOC_ENABLE_VERITY.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) * kernel_write() can't be used because the file descriptor is readonly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) static int pagecache_write(struct inode *inode, const void *buf, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) loff_t pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) if (pos + count > inode->i_sb->s_maxbytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return -EFBIG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) while (count) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) size_t n = min_t(size_t, count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) PAGE_SIZE - offset_in_page(pos));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) void *fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) void *addr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) int res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) res = pagecache_write_begin(NULL, inode->i_mapping, pos, n, 0,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) &page, &fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (res)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) addr = kmap_atomic(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) memcpy(addr + offset_in_page(pos), buf, n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) kunmap_atomic(addr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) res = pagecache_write_end(NULL, inode->i_mapping, pos, n, n,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) page, fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (res < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (res != n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) buf += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) pos += n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) count -= n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) static int ext4_begin_enable_verity(struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) struct inode *inode = file_inode(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) const int credits = 2; /* superblock and inode for ext4_orphan_add() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) handle_t *handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (IS_DAX(inode) || ext4_test_inode_flag(inode, EXT4_INODE_DAX))
^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) if (ext4_verity_in_progress(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) * Since the file was opened readonly, we have to initialize the jbd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) * inode and quotas here and not rely on ->open() doing it. This must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * be done before evicting the inline data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) err = ext4_inode_attach_jinode(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) err = dquot_initialize(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) err = ext4_convert_inline_data(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) ext4_warning_inode(inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) "verity is only allowed on extent-based files");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) return -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) }
^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) * ext4 uses the last allocated block to find the verity descriptor, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) * we must remove any other blocks past EOF which might confuse things.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) err = ext4_truncate(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) handle = ext4_journal_start(inode, EXT4_HT_INODE, credits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) if (IS_ERR(handle))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) return PTR_ERR(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) err = ext4_orphan_add(handle, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) if (err == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) ext4_set_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) ext4_journal_stop(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * ext4 stores the verity descriptor beginning on the next filesystem block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) * boundary after the Merkle tree. Then, the descriptor size is stored in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * last 4 bytes of the last allocated filesystem block --- which is either the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * block in which the descriptor ends, or the next block after that if there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) * weren't at least 4 bytes remaining.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * We can't simply store the descriptor in an xattr because it *must* be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * encrypted when ext4 encryption is used, but ext4 encryption doesn't encrypt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * xattrs. Also, if the descriptor includes a large signature blob it may be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * too large to store in an xattr without the EA_INODE feature.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) static int ext4_write_verity_descriptor(struct inode *inode, const void *desc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) size_t desc_size, u64 merkle_tree_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) const u64 desc_pos = round_up(ext4_verity_metadata_pos(inode) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) merkle_tree_size, i_blocksize(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) const u64 desc_end = desc_pos + desc_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) const __le32 desc_size_disk = cpu_to_le32(desc_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) const u64 desc_size_pos = round_up(desc_end + sizeof(desc_size_disk),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) i_blocksize(inode)) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) sizeof(desc_size_disk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) err = pagecache_write(inode, desc, desc_size, desc_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return pagecache_write(inode, &desc_size_disk, sizeof(desc_size_disk),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) desc_size_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) static int ext4_end_enable_verity(struct file *filp, const void *desc,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) size_t desc_size, u64 merkle_tree_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) struct inode *inode = file_inode(filp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) const int credits = 2; /* superblock and inode for ext4_orphan_del() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) handle_t *handle;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) struct ext4_iloc iloc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) * If an error already occurred (which fs/verity/ signals by passing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) * desc == NULL), then only clean-up is needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) if (desc == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /* Append the verity descriptor. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) err = ext4_write_verity_descriptor(inode, desc, desc_size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) merkle_tree_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * Write all pages (both data and verity metadata). Note that this must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) * happen before clearing EXT4_STATE_VERITY_IN_PROGRESS; otherwise pages
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * beyond i_size won't be written properly. For crash consistency, this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) * also must happen before the verity inode flag gets persisted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) err = filemap_write_and_wait(inode->i_mapping);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) * Finally, set the verity inode flag and remove the inode from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * orphan list (in a single transaction).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) handle = ext4_journal_start(inode, EXT4_HT_INODE, credits);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) if (IS_ERR(handle)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) err = PTR_ERR(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) goto cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) err = ext4_orphan_del(handle, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) goto stop_and_cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) err = ext4_reserve_inode_write(handle, inode, &iloc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) goto stop_and_cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) ext4_set_inode_flag(inode, EXT4_INODE_VERITY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) ext4_set_inode_flags(inode, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) err = ext4_mark_iloc_dirty(handle, inode, &iloc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) goto stop_and_cleanup;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) ext4_journal_stop(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) ext4_clear_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) stop_and_cleanup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) ext4_journal_stop(handle);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) cleanup:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) * Verity failed to be enabled, so clean up by truncating any verity
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * metadata that was written beyond i_size (both from cache and from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * disk), removing the inode from the orphan list (if it wasn't done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) * already), and clearing EXT4_STATE_VERITY_IN_PROGRESS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) truncate_inode_pages(inode->i_mapping, inode->i_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) ext4_truncate(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) ext4_orphan_del(NULL, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) ext4_clear_inode_state(inode, EXT4_STATE_VERITY_IN_PROGRESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static int ext4_get_verity_descriptor_location(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) size_t *desc_size_ret,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) u64 *desc_pos_ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) struct ext4_ext_path *path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) struct ext4_extent *last_extent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) u32 end_lblk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) u64 desc_size_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) __le32 desc_size_disk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) u32 desc_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) u64 desc_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) * Descriptor size is in last 4 bytes of last allocated block.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * See ext4_write_verity_descriptor().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) EXT4_ERROR_INODE(inode, "verity file doesn't use extents");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) return -EFSCORRUPTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) if (IS_ERR(path))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) return PTR_ERR(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) last_extent = path[path->p_depth].p_ext;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) if (!last_extent) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) EXT4_ERROR_INODE(inode, "verity file has no extents");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) ext4_ext_drop_refs(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) kfree(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) return -EFSCORRUPTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) end_lblk = le32_to_cpu(last_extent->ee_block) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) ext4_ext_get_actual_len(last_extent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) desc_size_pos = (u64)end_lblk << inode->i_blkbits;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) ext4_ext_drop_refs(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) kfree(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) if (desc_size_pos < sizeof(desc_size_disk))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) desc_size_pos -= sizeof(desc_size_disk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) err = pagecache_read(inode, &desc_size_disk, sizeof(desc_size_disk),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) desc_size_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) desc_size = le32_to_cpu(desc_size_disk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * The descriptor is stored just before the desc_size_disk, but starting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * on a filesystem block boundary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) if (desc_size > INT_MAX || desc_size > desc_size_pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) desc_pos = round_down(desc_size_pos - desc_size, i_blocksize(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) if (desc_pos < ext4_verity_metadata_pos(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) goto bad;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) *desc_size_ret = desc_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) *desc_pos_ret = desc_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) bad:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) EXT4_ERROR_INODE(inode, "verity file corrupted; can't find descriptor");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) return -EFSCORRUPTED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) static int ext4_get_verity_descriptor(struct inode *inode, void *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) size_t buf_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) size_t desc_size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) u64 desc_pos = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) err = ext4_get_verity_descriptor_location(inode, &desc_size, &desc_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) if (buf_size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if (desc_size > buf_size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) return -ERANGE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) err = pagecache_read(inode, buf, desc_size, desc_pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) return desc_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) static struct page *ext4_read_merkle_tree_page(struct inode *inode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) pgoff_t index,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) unsigned long num_ra_pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) DEFINE_READAHEAD(ractl, NULL, inode->i_mapping, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) page = find_get_page_flags(inode->i_mapping, index, FGP_ACCESSED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) if (!page || !PageUptodate(page)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) if (page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) put_page(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) else if (num_ra_pages > 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) page_cache_ra_unbounded(&ractl, num_ra_pages, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) page = read_mapping_page(inode->i_mapping, index, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) return page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) static int ext4_write_merkle_tree_block(struct inode *inode, const void *buf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) u64 index, int log_blocksize)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) loff_t pos = ext4_verity_metadata_pos(inode) + (index << log_blocksize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) return pagecache_write(inode, buf, 1 << log_blocksize, pos);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) const struct fsverity_operations ext4_verityops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) .begin_enable_verity = ext4_begin_enable_verity,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) .end_enable_verity = ext4_end_enable_verity,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) .get_verity_descriptor = ext4_get_verity_descriptor,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) .read_merkle_tree_page = ext4_read_merkle_tree_page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) .write_merkle_tree_block = ext4_write_merkle_tree_block,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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