diff options
Diffstat (limited to 'drivers/md/dm-verity.c')
| -rw-r--r-- | drivers/md/dm-verity.c | 102 |
1 files changed, 91 insertions, 11 deletions
diff --git a/drivers/md/dm-verity.c b/drivers/md/dm-verity.c index 7a7bab8947ae..32a6a8130557 100644 --- a/drivers/md/dm-verity.c +++ b/drivers/md/dm-verity.c @@ -18,20 +18,36 @@ #include <linux/module.h> #include <linux/device-mapper.h> +#include <linux/reboot.h> #include <crypto/hash.h> #define DM_MSG_PREFIX "verity" +#define DM_VERITY_ENV_LENGTH 42 +#define DM_VERITY_ENV_VAR_NAME "VERITY_ERR_BLOCK_NR" + #define DM_VERITY_IO_VEC_INLINE 16 #define DM_VERITY_MEMPOOL_SIZE 4 #define DM_VERITY_DEFAULT_PREFETCH_SIZE 262144 #define DM_VERITY_MAX_LEVELS 63 +#define DM_VERITY_MAX_CORRUPTED_ERRS 100 static unsigned dm_verity_prefetch_cluster = DM_VERITY_DEFAULT_PREFETCH_SIZE; module_param_named(prefetch_cluster, dm_verity_prefetch_cluster, uint, S_IRUGO | S_IWUSR); +enum verity_mode { + DM_VERITY_MODE_EIO = 0, + DM_VERITY_MODE_LOGGING = 1, + DM_VERITY_MODE_RESTART = 2 +}; + +enum verity_block_type { + DM_VERITY_BLOCK_TYPE_DATA, + DM_VERITY_BLOCK_TYPE_METADATA +}; + struct dm_verity { struct dm_dev *data_dev; struct dm_dev *hash_dev; @@ -54,6 +70,8 @@ struct dm_verity { unsigned digest_size; /* digest size for the current hash algorithm */ unsigned shash_descsize;/* the size of temporary space for crypto */ int hash_failed; /* set to 1 if hash of any block failed */ + enum verity_mode mode; /* mode for handling verification errors */ + unsigned corrupted_errs;/* Number of errors for corrupted blocks */ mempool_t *vec_mempool; /* mempool of bio vector */ @@ -175,6 +193,54 @@ static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level, } /* + * Handle verification errors. + */ +static int verity_handle_err(struct dm_verity *v, enum verity_block_type type, + unsigned long long block) +{ + char verity_env[DM_VERITY_ENV_LENGTH]; + char *envp[] = { verity_env, NULL }; + const char *type_str = ""; + struct mapped_device *md = dm_table_get_md(v->ti->table); + + if (v->corrupted_errs >= DM_VERITY_MAX_CORRUPTED_ERRS) + goto out; + + ++v->corrupted_errs; + + switch (type) { + case DM_VERITY_BLOCK_TYPE_DATA: + type_str = "data"; + break; + case DM_VERITY_BLOCK_TYPE_METADATA: + type_str = "metadata"; + break; + default: + BUG(); + } + + DMERR_LIMIT("%s: %s block %llu is corrupted", v->data_dev->name, + type_str, block); + + if (v->corrupted_errs == DM_VERITY_MAX_CORRUPTED_ERRS) + DMERR("%s: reached maximum errors", v->data_dev->name); + + snprintf(verity_env, DM_VERITY_ENV_LENGTH, "%s=%d,%llu", + DM_VERITY_ENV_VAR_NAME, type, block); + + kobject_uevent_env(&disk_to_dev(dm_disk(md))->kobj, KOBJ_CHANGE, envp); + +out: + if (v->mode == DM_VERITY_MODE_LOGGING) + return 0; + + if (v->mode == DM_VERITY_MODE_RESTART) + kernel_restart("dm-verity device corrupted"); + + return 1; +} + +/* * Verify hash of a metadata block pertaining to the specified data block * ("block" argument) at a specified level ("level" argument). * @@ -251,11 +317,13 @@ static int verity_verify_level(struct dm_verity_io *io, sector_t block, goto release_ret_r; } if (unlikely(memcmp(result, io_want_digest(v, io), v->digest_size))) { - DMERR_LIMIT("metadata block %llu is corrupted", - (unsigned long long)hash_block); v->hash_failed = 1; - r = -EIO; - goto release_ret_r; + + if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_METADATA, + hash_block)) { + r = -EIO; + goto release_ret_r; + } } else aux->hash_verified = 1; } @@ -367,10 +435,11 @@ test_block_hash: return r; } if (unlikely(memcmp(result, io_want_digest(v, io), v->digest_size))) { - DMERR_LIMIT("data block %llu is corrupted", - (unsigned long long)(io->block + b)); v->hash_failed = 1; - return -EIO; + + if (verity_handle_err(v, DM_VERITY_BLOCK_TYPE_DATA, + io->block + b)) + return -EIO; } } @@ -668,14 +737,14 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) goto bad; } - if (argc != 10) { - ti->error = "Invalid argument count: exactly 10 arguments required"; + if (argc < 10 || argc > 11) { + ti->error = "Invalid argument count: 10-11 arguments required"; r = -EINVAL; goto bad; } - if (sscanf(argv[0], "%u%c", &num, &dummy) != 1 || - num > 1) { + if (sscanf(argv[0], "%d%c", &num, &dummy) != 1 || + num < 0 || num > 1) { ti->error = "Invalid version"; r = -EINVAL; goto bad; @@ -790,6 +859,17 @@ static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv) } } + if (argc > 10) { + if (sscanf(argv[10], "%d%c", &num, &dummy) != 1 || + num < DM_VERITY_MODE_EIO || + num > DM_VERITY_MODE_RESTART) { + ti->error = "Invalid mode"; + r = -EINVAL; + goto bad; + } + v->mode = num; + } + v->hash_per_block_bits = __fls((1 << v->hash_dev_block_bits) / v->digest_size); |