Calculate and verify a checksum covering the journal superblock.
Unified · Split
| @@ -106,6 +106,34 @@ int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb) · 105 unmodified lines | ||
| 106 | 106 | return sb->s_checksum_type == JBD2_CRC32C_CHKSUM; |
| 107 | 107 | } |
| 108 | 108 | |
| 109 | +static __u32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb) | |
| 110 | +{ | |
| 111 | + __u32 csum, old_csum; | |
| 112 | + | |
| 113 | + old_csum = sb->s_checksum; | |
| 114 | + sb->s_checksum = 0; | |
| 115 | + csum = jbd2_chksum(j, ~0, (char *)sb, sizeof(journal_superblock_t)); | |
| 116 | + sb->s_checksum = old_csum; | |
| 117 | + | |
| 118 | + return cpu_to_be32(csum); | |
| 119 | +} | |
| 120 | + | |
| 121 | +int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb) | |
| 122 | +{ | |
| 123 | + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) | |
| 124 | + return 1; | |
| 125 | + | |
| 126 | + return sb->s_checksum == jbd2_superblock_csum(j, sb); | |
| 127 | +} | |
| 128 | + | |
| 129 | +void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb) | |
| 130 | +{ | |
| 131 | + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) | |
| 132 | + return; | |
| 133 | + | |
| 134 | + sb->s_checksum = jbd2_superblock_csum(j, sb); | |
| 135 | +} | |
| 136 | + | |
| 109 | 137 | /* |
| 110 | 138 | * Helper function used to manage commit timeouts |
| 111 | 139 | */ |
| @@ -1357,6 +1385,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal) · 1245 unmodified lines | ||
| 1357 | 1385 | jbd_debug(1, "JBD2: updating superblock error (errno %d)\n", |
| 1358 | 1386 | journal->j_errno); |
| 1359 | 1387 | sb->s_errno = cpu_to_be32(journal->j_errno); |
| 1388 | + jbd2_superblock_csum_set(journal, sb); | |
| 1360 | 1389 | read_unlock(&journal->j_state_lock); |
| 1361 | 1390 | |
| 1362 | 1391 | jbd2_write_superblock(journal, WRITE_SYNC); |
| @@ -1449,6 +1478,17 @@ static int journal_get_superblock(journal_t *journal) · 86 unmodified lines | ||
| 1449 | 1478 | } |
| 1450 | 1479 | } |
| 1451 | 1480 | |
| 1481 | + /* Check superblock checksum */ | |
| 1482 | + if (!jbd2_superblock_csum_verify(journal, sb)) { | |
| 1483 | + printk(KERN_ERR "JBD: journal checksum error\n"); | |
| 1484 | + goto out; | |
| 1485 | + } | |
| 1486 | + | |
| 1487 | + /* Precompute checksum seed for all metadata */ | |
| 1488 | + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) | |
| 1489 | + journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid, | |
| 1490 | + sizeof(sb->s_uuid)); | |
| 1491 | + | |
| 1452 | 1492 | set_buffer_verified(bh); |
| 1453 | 1493 | |
| 1454 | 1494 | return 0; |
| @@ -1732,6 +1772,13 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat, · 277 unmodified lines | ||
| 1732 | 1772 | return 0; |
| 1733 | 1773 | } |
| 1734 | 1774 | } |
| 1775 | + | |
| 1776 | + /* Precompute checksum seed for all metadata */ | |
| 1777 | + if (JBD2_HAS_INCOMPAT_FEATURE(journal, | |
| 1778 | + JBD2_FEATURE_INCOMPAT_CSUM_V2)) | |
| 1779 | + journal->j_csum_seed = jbd2_chksum(journal, ~0, | |
| 1780 | + sb->s_uuid, | |
| 1781 | + sizeof(sb->s_uuid)); | |
| 1735 | 1782 | } |
| 1736 | 1783 | |
| 1737 | 1784 | /* If enabling v1 checksums, downgrade superblock */ |
| @@ -969,6 +969,9 @@ struct journal_s · 968 unmodified lines | ||
| 969 | 969 | |
| 970 | 970 | /* Reference to checksum algorithm driver via cryptoapi */ |
| 971 | 971 | struct crypto_shash *j_chksum_driver; |
| 972 | + | |
| 973 | + /* Precomputed journal UUID checksum for seeding other checksums */ | |
| 974 | + __u32 j_csum_seed; | |
| 972 | 975 | }; |
| 973 | 976 | |
| 974 | 977 | /* |