diff options
| -rw-r--r-- | Documentation/device-mapper/dm-integrity.txt | 7 | ||||
| -rw-r--r-- | drivers/md/dm-integrity.c | 24 |
2 files changed, 30 insertions, 1 deletions
diff --git a/Documentation/device-mapper/dm-integrity.txt b/Documentation/device-mapper/dm-integrity.txt index 297251b0d2d5..bf6af2ade0a6 100644 --- a/Documentation/device-mapper/dm-integrity.txt +++ b/Documentation/device-mapper/dm-integrity.txt @@ -146,6 +146,13 @@ block_size:number Supported values are 512, 1024, 2048 and 4096 bytes. If not specified the default block size is 512 bytes. +legacy_recalculate + Allow recalculating of volumes with HMAC keys. This is disabled by + default for security reasons - an attacker could modify the volume, + set recalc_sector to zero, and the kernel would not detect the + modification. + + The journal mode (D/J), buffer_sectors, journal_watermark, commit_time can be changed when reloading the target (load an inactive table and swap the tables with suspend and resume). The other arguments should not be changed diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 1917051b512f..cffd42317272 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -240,6 +240,7 @@ struct dm_integrity_c { bool journal_uptodate; bool just_formatted; + bool legacy_recalculate; struct alg_spec internal_hash_alg; struct alg_spec journal_crypt_alg; @@ -345,6 +346,14 @@ static int dm_integrity_failed(struct dm_integrity_c *ic) return READ_ONCE(ic->failed); } +static bool dm_integrity_disable_recalculate(struct dm_integrity_c *ic) +{ + if ((ic->internal_hash_alg.key || ic->journal_mac_alg.key) && + !ic->legacy_recalculate) + return true; + return false; +} + static commit_id_t dm_integrity_commit_id(struct dm_integrity_c *ic, unsigned i, unsigned j, unsigned char seq) { @@ -2503,6 +2512,7 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type, arg_count += !!ic->internal_hash_alg.alg_string; arg_count += !!ic->journal_crypt_alg.alg_string; arg_count += !!ic->journal_mac_alg.alg_string; + arg_count += ic->legacy_recalculate; DMEMIT("%s %llu %u %c %u", ic->dev->name, (unsigned long long)ic->start, ic->tag_size, ic->mode, arg_count); if (ic->meta_dev) @@ -2516,6 +2526,8 @@ static void dm_integrity_status(struct dm_target *ti, status_type_t type, DMEMIT(" buffer_sectors:%u", 1U << ic->log2_buffer_sectors); DMEMIT(" journal_watermark:%u", (unsigned)watermark_percentage); DMEMIT(" commit_time:%u", ic->autocommit_msec); + if (ic->legacy_recalculate) + DMEMIT(" legacy_recalculate"); #define EMIT_ALG(a, n) \ do { \ @@ -3118,7 +3130,7 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) unsigned extra_args; struct dm_arg_set as; static const struct dm_arg _args[] = { - {0, 15, "Invalid number of feature args"}, + {0, 12, "Invalid number of feature args"}, }; unsigned journal_sectors, interleave_sectors, buffer_sectors, journal_watermark, sync_msec; bool recalculate; @@ -3248,6 +3260,8 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } else if (!strcmp(opt_string, "recalculate")) { recalculate = true; + } else if (!strcmp(opt_string, "legacy_recalculate")) { + ic->legacy_recalculate = true; } else { r = -EINVAL; ti->error = "Invalid argument"; @@ -3523,6 +3537,14 @@ try_smaller_buffer: } } + if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING) && + le64_to_cpu(ic->sb->recalc_sector) < ic->provided_data_sectors && + dm_integrity_disable_recalculate(ic)) { + ti->error = "Recalculating with HMAC is disabled for security reasons - if you really need it, use the argument \"legacy_recalculate\""; + r = -EOPNOTSUPP; + goto bad; + } + ic->bufio = dm_bufio_client_create(ic->meta_dev ? ic->meta_dev->bdev : ic->dev->bdev, 1U << (SECTOR_SHIFT + ic->log2_buffer_sectors), 1, 0, NULL, NULL); if (IS_ERR(ic->bufio)) { |