Merge tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar...
authorLinus Torvalds <torvalds@linux-foundation.org>
Thu, 2 Sep 2021 19:51:41 +0000 (12:51 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 2 Sep 2021 19:51:41 +0000 (12:51 -0700)
Pull integrity subsystem updates from Mimi Zohar:

 - Limit the allowed hash algorithms when writing security.ima xattrs or
   verifying them, based on the IMA policy and the configured hash
   algorithms.

 - Return the calculated "critical data" measurement hash and size to
   avoid code duplication. (Preparatory change for a proposed LSM.)

 - and a single patch to address a compiler warning.

* tag 'integrity-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  IMA: reject unknown hash algorithms in ima_get_hash_algo
  IMA: prevent SETXATTR_CHECK policy rules with unavailable algorithms
  IMA: introduce a new policy option func=SETXATTR_CHECK
  IMA: add a policy option to restrict xattr hash algorithms on appraisal
  IMA: add support to restrict the hash algorithms used for file appraisal
  IMA: block writes of the security.ima xattr with unsupported algorithms
  IMA: remove the dependency on CRYPTO_MD5
  ima: Add digest and digest_len params to the functions to measure a buffer
  ima: Return int in the functions to measure a buffer
  ima: Introduce ima_get_current_hash_algo()
  IMA: remove -Wmissing-prototypes warning

1  2 
drivers/md/dm-ima.c
security/integrity/ima/ima_main.c

index 3fd69ab12a8e7798e93cc916e9b1965498fdceca,0000000000000000000000000000000000000000..2c5edfbd771179c389da28ccbf8ad05de94d25f1
mode 100644,000000..100644
--- /dev/null
@@@ -1,750 -1,0 +1,751 @@@
-       ima_measure_critical_data(DM_NAME, event_name, buf, buf_len, false);
 +// SPDX-License-Identifier: GPL-2.0
 +/*
 + * Copyright (C) 2021 Microsoft Corporation
 + *
 + * Author: Tushar Sugandhi <tusharsu@linux.microsoft.com>
 + *
 + * File: dm-ima.c
 + *       Enables IMA measurements for DM targets
 + */
 +
 +#include "dm-core.h"
 +#include "dm-ima.h"
 +
 +#include <linux/ima.h>
 +#include <crypto/hash.h>
 +#include <linux/crypto.h>
 +#include <crypto/hash_info.h>
 +
 +#define DM_MSG_PREFIX "ima"
 +
 +/*
 + * Internal function to prefix separator characters in input buffer with escape
 + * character, so that they don't interfere with the construction of key-value pairs,
 + * and clients can split the key1=val1,key2=val2,key3=val3; pairs properly.
 + */
 +static void fix_separator_chars(char **buf)
 +{
 +      int l = strlen(*buf);
 +      int i, j, sp = 0;
 +
 +      for (i = 0; i < l; i++)
 +              if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
 +                      sp++;
 +
 +      if (!sp)
 +              return;
 +
 +      for (i = l-1, j = i+sp; i >= 0; i--) {
 +              (*buf)[j--] = (*buf)[i];
 +              if ((*buf)[i] == '\\' || (*buf)[i] == ';' || (*buf)[i] == '=' || (*buf)[i] == ',')
 +                      (*buf)[j--] = '\\';
 +      }
 +}
 +
 +/*
 + * Internal function to allocate memory for IMA measurements.
 + */
 +static void *dm_ima_alloc(size_t len, gfp_t flags, bool noio)
 +{
 +      unsigned int noio_flag;
 +      void *ptr;
 +
 +      if (noio)
 +              noio_flag = memalloc_noio_save();
 +
 +      ptr = kzalloc(len, flags);
 +
 +      if (noio)
 +              memalloc_noio_restore(noio_flag);
 +
 +      return ptr;
 +}
 +
 +/*
 + * Internal function to allocate and copy name and uuid for IMA measurements.
 + */
 +static int dm_ima_alloc_and_copy_name_uuid(struct mapped_device *md, char **dev_name,
 +                                         char **dev_uuid, bool noio)
 +{
 +      int r;
 +      *dev_name = dm_ima_alloc(DM_NAME_LEN*2, GFP_KERNEL, noio);
 +      if (!(*dev_name)) {
 +              r = -ENOMEM;
 +              goto error;
 +      }
 +
 +      *dev_uuid = dm_ima_alloc(DM_UUID_LEN*2, GFP_KERNEL, noio);
 +      if (!(*dev_uuid)) {
 +              r = -ENOMEM;
 +              goto error;
 +      }
 +
 +      r = dm_copy_name_and_uuid(md, *dev_name, *dev_uuid);
 +      if (r)
 +              goto error;
 +
 +      fix_separator_chars(dev_name);
 +      fix_separator_chars(dev_uuid);
 +
 +      return 0;
 +error:
 +      kfree(*dev_name);
 +      kfree(*dev_uuid);
 +      *dev_name = NULL;
 +      *dev_uuid = NULL;
 +      return r;
 +}
 +
 +/*
 + * Internal function to allocate and copy device data for IMA measurements.
 + */
 +static int dm_ima_alloc_and_copy_device_data(struct mapped_device *md, char **device_data,
 +                                           unsigned int num_targets, bool noio)
 +{
 +      char *dev_name = NULL, *dev_uuid = NULL;
 +      int r;
 +
 +      r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
 +      if (r)
 +              return r;
 +
 +      *device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
 +      if (!(*device_data)) {
 +              r = -ENOMEM;
 +              goto error;
 +      }
 +
 +      scnprintf(*device_data, DM_IMA_DEVICE_BUF_LEN,
 +                "name=%s,uuid=%s,major=%d,minor=%d,minor_count=%d,num_targets=%u;",
 +                dev_name, dev_uuid, md->disk->major, md->disk->first_minor,
 +                md->disk->minors, num_targets);
 +error:
 +      kfree(dev_name);
 +      kfree(dev_uuid);
 +      return r;
 +}
 +
 +/*
 + * Internal wrapper function to call IMA to measure DM data.
 + */
 +static void dm_ima_measure_data(const char *event_name, const void *buf, size_t buf_len,
 +                              bool noio)
 +{
 +      unsigned int noio_flag;
 +
 +      if (noio)
 +              noio_flag = memalloc_noio_save();
 +
++      ima_measure_critical_data(DM_NAME, event_name, buf, buf_len,
++                                false, NULL, 0);
 +
 +      if (noio)
 +              memalloc_noio_restore(noio_flag);
 +}
 +
 +/*
 + * Internal function to allocate and copy current device capacity for IMA measurements.
 + */
 +static int dm_ima_alloc_and_copy_capacity_str(struct mapped_device *md, char **capacity_str,
 +                                            bool noio)
 +{
 +      sector_t capacity;
 +
 +      capacity = get_capacity(md->disk);
 +
 +      *capacity_str = dm_ima_alloc(DM_IMA_DEVICE_CAPACITY_BUF_LEN, GFP_KERNEL, noio);
 +      if (!(*capacity_str))
 +              return -ENOMEM;
 +
 +      scnprintf(*capacity_str, DM_IMA_DEVICE_BUF_LEN, "current_device_capacity=%llu;",
 +                capacity);
 +
 +      return 0;
 +}
 +
 +/*
 + * Initialize/reset the dm ima related data structure variables.
 + */
 +void dm_ima_reset_data(struct mapped_device *md)
 +{
 +      memset(&(md->ima), 0, sizeof(md->ima));
 +      md->ima.dm_version_str_len = strlen(DM_IMA_VERSION_STR);
 +}
 +
 +/*
 + * Build up the IMA data for each target, and finally measure.
 + */
 +void dm_ima_measure_on_table_load(struct dm_table *table, unsigned int status_flags)
 +{
 +      size_t device_data_buf_len, target_metadata_buf_len, target_data_buf_len, l = 0;
 +      char *target_metadata_buf = NULL, *target_data_buf = NULL, *digest_buf = NULL;
 +      char *ima_buf = NULL, *device_data_buf = NULL;
 +      int digest_size, last_target_measured = -1, r;
 +      status_type_t type = STATUSTYPE_IMA;
 +      size_t cur_total_buf_len = 0;
 +      unsigned int num_targets, i;
 +      SHASH_DESC_ON_STACK(shash, NULL);
 +      struct crypto_shash *tfm = NULL;
 +      u8 *digest = NULL;
 +      bool noio = false;
 +      /*
 +       * In below hash_alg_prefix_len assignment +1 is for the additional char (':'),
 +       * when prefixing the hash value with the hash algorithm name. e.g. sha256:<hash_value>.
 +       */
 +      const size_t hash_alg_prefix_len = strlen(DM_IMA_TABLE_HASH_ALG) + 1;
 +      char table_load_event_name[] = "dm_table_load";
 +
 +      ima_buf = dm_ima_alloc(DM_IMA_MEASUREMENT_BUF_LEN, GFP_KERNEL, noio);
 +      if (!ima_buf)
 +              return;
 +
 +      target_metadata_buf = dm_ima_alloc(DM_IMA_TARGET_METADATA_BUF_LEN, GFP_KERNEL, noio);
 +      if (!target_metadata_buf)
 +              goto error;
 +
 +      target_data_buf = dm_ima_alloc(DM_IMA_TARGET_DATA_BUF_LEN, GFP_KERNEL, noio);
 +      if (!target_data_buf)
 +              goto error;
 +
 +      num_targets = dm_table_get_num_targets(table);
 +
 +      if (dm_ima_alloc_and_copy_device_data(table->md, &device_data_buf, num_targets, noio))
 +              goto error;
 +
 +      tfm = crypto_alloc_shash(DM_IMA_TABLE_HASH_ALG, 0, 0);
 +      if (IS_ERR(tfm))
 +              goto error;
 +
 +      shash->tfm = tfm;
 +      digest_size = crypto_shash_digestsize(tfm);
 +      digest = dm_ima_alloc(digest_size, GFP_KERNEL, noio);
 +      if (!digest)
 +              goto error;
 +
 +      r = crypto_shash_init(shash);
 +      if (r)
 +              goto error;
 +
 +      memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
 +      l += table->md->ima.dm_version_str_len;
 +
 +      device_data_buf_len = strlen(device_data_buf);
 +      memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
 +      l += device_data_buf_len;
 +
 +      for (i = 0; i < num_targets; i++) {
 +              struct dm_target *ti = dm_table_get_target(table, i);
 +
 +              if (!ti)
 +                      goto error;
 +
 +              last_target_measured = 0;
 +
 +              /*
 +               * First retrieve the target metadata.
 +               */
 +              scnprintf(target_metadata_buf, DM_IMA_TARGET_METADATA_BUF_LEN,
 +                        "target_index=%d,target_begin=%llu,target_len=%llu,",
 +                        i, ti->begin, ti->len);
 +              target_metadata_buf_len = strlen(target_metadata_buf);
 +
 +              /*
 +               * Then retrieve the actual target data.
 +               */
 +              if (ti->type->status)
 +                      ti->type->status(ti, type, status_flags, target_data_buf,
 +                                       DM_IMA_TARGET_DATA_BUF_LEN);
 +              else
 +                      target_data_buf[0] = '\0';
 +
 +              target_data_buf_len = strlen(target_data_buf);
 +
 +              /*
 +               * Check if the total data can fit into the IMA buffer.
 +               */
 +              cur_total_buf_len = l + target_metadata_buf_len + target_data_buf_len;
 +
 +              /*
 +               * IMA measurements for DM targets are best-effort.
 +               * If the total data buffered so far, including the current target,
 +               * is too large to fit into DM_IMA_MEASUREMENT_BUF_LEN, measure what
 +               * we have in the current buffer, and continue measuring the remaining
 +               * targets by prefixing the device metadata again.
 +               */
 +              if (unlikely(cur_total_buf_len >= DM_IMA_MEASUREMENT_BUF_LEN)) {
 +                      dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
 +                      r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
 +                      if (r < 0)
 +                              goto error;
 +
 +                      memset(ima_buf, 0, DM_IMA_MEASUREMENT_BUF_LEN);
 +                      l = 0;
 +
 +                      /*
 +                       * Each new "dm_table_load" entry in IMA log should have device data
 +                       * prefix, so that multiple records from the same "dm_table_load" for
 +                       * a given device can be linked together.
 +                       */
 +                      memcpy(ima_buf + l, DM_IMA_VERSION_STR, table->md->ima.dm_version_str_len);
 +                      l += table->md->ima.dm_version_str_len;
 +
 +                      memcpy(ima_buf + l, device_data_buf, device_data_buf_len);
 +                      l += device_data_buf_len;
 +
 +                      /*
 +                       * If this iteration of the for loop turns out to be the last target
 +                       * in the table, dm_ima_measure_data("dm_table_load", ...) doesn't need
 +                       * to be called again, just the hash needs to be finalized.
 +                       * "last_target_measured" tracks this state.
 +                       */
 +                      last_target_measured = 1;
 +              }
 +
 +              /*
 +               * Fill-in all the target metadata, so that multiple targets for the same
 +               * device can be linked together.
 +               */
 +              memcpy(ima_buf + l, target_metadata_buf, target_metadata_buf_len);
 +              l += target_metadata_buf_len;
 +
 +              memcpy(ima_buf + l, target_data_buf, target_data_buf_len);
 +              l += target_data_buf_len;
 +      }
 +
 +      if (!last_target_measured) {
 +              dm_ima_measure_data(table_load_event_name, ima_buf, l, noio);
 +
 +              r = crypto_shash_update(shash, (const u8 *)ima_buf, l);
 +              if (r < 0)
 +                      goto error;
 +      }
 +
 +      /*
 +       * Finalize the table hash, and store it in table->md->ima.inactive_table.hash,
 +       * so that the table data can be verified against the future device state change
 +       * events, e.g. resume, rename, remove, table-clear etc.
 +       */
 +      r = crypto_shash_final(shash, digest);
 +      if (r < 0)
 +              goto error;
 +
 +      digest_buf = dm_ima_alloc((digest_size*2) + hash_alg_prefix_len + 1, GFP_KERNEL, noio);
 +
 +      if (!digest_buf)
 +              goto error;
 +
 +      snprintf(digest_buf, hash_alg_prefix_len + 1, "%s:", DM_IMA_TABLE_HASH_ALG);
 +
 +      for (i = 0; i < digest_size; i++)
 +              snprintf((digest_buf + hash_alg_prefix_len + (i*2)), 3, "%02x", digest[i]);
 +
 +      if (table->md->ima.active_table.hash != table->md->ima.inactive_table.hash)
 +              kfree(table->md->ima.inactive_table.hash);
 +
 +      table->md->ima.inactive_table.hash = digest_buf;
 +      table->md->ima.inactive_table.hash_len = strlen(digest_buf);
 +      table->md->ima.inactive_table.num_targets = num_targets;
 +
 +      if (table->md->ima.active_table.device_metadata !=
 +          table->md->ima.inactive_table.device_metadata)
 +              kfree(table->md->ima.inactive_table.device_metadata);
 +
 +      table->md->ima.inactive_table.device_metadata = device_data_buf;
 +      table->md->ima.inactive_table.device_metadata_len = device_data_buf_len;
 +
 +      goto exit;
 +error:
 +      kfree(digest_buf);
 +      kfree(device_data_buf);
 +exit:
 +      kfree(digest);
 +      if (tfm)
 +              crypto_free_shash(tfm);
 +      kfree(ima_buf);
 +      kfree(target_metadata_buf);
 +      kfree(target_data_buf);
 +}
 +
 +/*
 + * Measure IMA data on device resume.
 + */
 +void dm_ima_measure_on_device_resume(struct mapped_device *md, bool swap)
 +{
 +      char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
 +      char active[] = "active_table_hash=";
 +      unsigned int active_len = strlen(active), capacity_len = 0;
 +      unsigned int l = 0;
 +      bool noio = true;
 +      bool nodata = true;
 +      int r;
 +
 +      device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
 +      if (!device_table_data)
 +              return;
 +
 +      r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
 +      if (r)
 +              goto error;
 +
 +      memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
 +      l += md->ima.dm_version_str_len;
 +
 +      if (swap) {
 +              if (md->ima.active_table.hash != md->ima.inactive_table.hash)
 +                      kfree(md->ima.active_table.hash);
 +
 +              md->ima.active_table.hash = NULL;
 +              md->ima.active_table.hash_len = 0;
 +
 +              if (md->ima.active_table.device_metadata !=
 +                  md->ima.inactive_table.device_metadata)
 +                      kfree(md->ima.active_table.device_metadata);
 +
 +              md->ima.active_table.device_metadata = NULL;
 +              md->ima.active_table.device_metadata_len = 0;
 +              md->ima.active_table.num_targets = 0;
 +
 +              if (md->ima.inactive_table.hash) {
 +                      md->ima.active_table.hash = md->ima.inactive_table.hash;
 +                      md->ima.active_table.hash_len = md->ima.inactive_table.hash_len;
 +                      md->ima.inactive_table.hash = NULL;
 +                      md->ima.inactive_table.hash_len = 0;
 +              }
 +
 +              if (md->ima.inactive_table.device_metadata) {
 +                      md->ima.active_table.device_metadata =
 +                              md->ima.inactive_table.device_metadata;
 +                      md->ima.active_table.device_metadata_len =
 +                              md->ima.inactive_table.device_metadata_len;
 +                      md->ima.active_table.num_targets = md->ima.inactive_table.num_targets;
 +                      md->ima.inactive_table.device_metadata = NULL;
 +                      md->ima.inactive_table.device_metadata_len = 0;
 +                      md->ima.inactive_table.num_targets = 0;
 +              }
 +      }
 +
 +      if (md->ima.active_table.device_metadata) {
 +              memcpy(device_table_data + l, md->ima.active_table.device_metadata,
 +                     md->ima.active_table.device_metadata_len);
 +              l += md->ima.active_table.device_metadata_len;
 +
 +              nodata = false;
 +      }
 +
 +      if (md->ima.active_table.hash) {
 +              memcpy(device_table_data + l, active, active_len);
 +              l += active_len;
 +
 +              memcpy(device_table_data + l, md->ima.active_table.hash,
 +                     md->ima.active_table.hash_len);
 +              l += md->ima.active_table.hash_len;
 +
 +              memcpy(device_table_data + l, ";", 1);
 +              l++;
 +
 +              nodata = false;
 +      }
 +
 +      if (nodata) {
 +              r = dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio);
 +              if (r)
 +                      goto error;
 +
 +              scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
 +                        "%sname=%s,uuid=%s;device_resume=no_data;",
 +                        DM_IMA_VERSION_STR, dev_name, dev_uuid);
 +              l += strlen(device_table_data);
 +
 +      }
 +
 +      capacity_len = strlen(capacity_str);
 +      memcpy(device_table_data + l, capacity_str, capacity_len);
 +      l += capacity_len;
 +
 +      dm_ima_measure_data("dm_device_resume", device_table_data, l, noio);
 +
 +      kfree(dev_name);
 +      kfree(dev_uuid);
 +error:
 +      kfree(capacity_str);
 +      kfree(device_table_data);
 +}
 +
 +/*
 + * Measure IMA data on remove.
 + */
 +void dm_ima_measure_on_device_remove(struct mapped_device *md, bool remove_all)
 +{
 +      char *device_table_data, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
 +      char active_table_str[] = "active_table_hash=";
 +      char inactive_table_str[] = "inactive_table_hash=";
 +      char device_active_str[] = "device_active_metadata=";
 +      char device_inactive_str[] = "device_inactive_metadata=";
 +      char remove_all_str[] = "remove_all=";
 +      unsigned int active_table_len = strlen(active_table_str);
 +      unsigned int inactive_table_len = strlen(inactive_table_str);
 +      unsigned int device_active_len = strlen(device_active_str);
 +      unsigned int device_inactive_len = strlen(device_inactive_str);
 +      unsigned int remove_all_len = strlen(remove_all_str);
 +      unsigned int capacity_len = 0;
 +      unsigned int l = 0;
 +      bool noio = true;
 +      bool nodata = true;
 +      int r;
 +
 +      device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN*2, GFP_KERNEL, noio);
 +      if (!device_table_data)
 +              goto exit;
 +
 +      r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
 +      if (r) {
 +              kfree(device_table_data);
 +              goto exit;
 +      }
 +
 +      memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
 +      l += md->ima.dm_version_str_len;
 +
 +      if (md->ima.active_table.device_metadata) {
 +              memcpy(device_table_data + l, device_active_str, device_active_len);
 +              l += device_active_len;
 +
 +              memcpy(device_table_data + l, md->ima.active_table.device_metadata,
 +                     md->ima.active_table.device_metadata_len);
 +              l += md->ima.active_table.device_metadata_len;
 +
 +              nodata = false;
 +      }
 +
 +      if (md->ima.inactive_table.device_metadata) {
 +              memcpy(device_table_data + l, device_inactive_str, device_inactive_len);
 +              l += device_inactive_len;
 +
 +              memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
 +                     md->ima.inactive_table.device_metadata_len);
 +              l += md->ima.inactive_table.device_metadata_len;
 +
 +              nodata = false;
 +      }
 +
 +      if (md->ima.active_table.hash) {
 +              memcpy(device_table_data + l, active_table_str, active_table_len);
 +              l += active_table_len;
 +
 +              memcpy(device_table_data + l, md->ima.active_table.hash,
 +                         md->ima.active_table.hash_len);
 +              l += md->ima.active_table.hash_len;
 +
 +              memcpy(device_table_data + l, ",", 1);
 +              l++;
 +
 +              nodata = false;
 +      }
 +
 +      if (md->ima.inactive_table.hash) {
 +              memcpy(device_table_data + l, inactive_table_str, inactive_table_len);
 +              l += inactive_table_len;
 +
 +              memcpy(device_table_data + l, md->ima.inactive_table.hash,
 +                     md->ima.inactive_table.hash_len);
 +              l += md->ima.inactive_table.hash_len;
 +
 +              memcpy(device_table_data + l, ",", 1);
 +              l++;
 +
 +              nodata = false;
 +      }
 +      /*
 +       * In case both active and inactive tables, and corresponding
 +       * device metadata is cleared/missing - record the name and uuid
 +       * in IMA measurements.
 +       */
 +      if (nodata) {
 +              if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
 +                      goto error;
 +
 +              scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
 +                        "%sname=%s,uuid=%s;device_remove=no_data;",
 +                        DM_IMA_VERSION_STR, dev_name, dev_uuid);
 +              l += strlen(device_table_data);
 +      }
 +
 +      memcpy(device_table_data + l, remove_all_str, remove_all_len);
 +      l += remove_all_len;
 +      memcpy(device_table_data + l, remove_all ? "y;" : "n;", 2);
 +      l += 2;
 +
 +      capacity_len = strlen(capacity_str);
 +      memcpy(device_table_data + l, capacity_str, capacity_len);
 +      l += capacity_len;
 +
 +      dm_ima_measure_data("dm_device_remove", device_table_data, l, noio);
 +
 +error:
 +      kfree(device_table_data);
 +      kfree(capacity_str);
 +exit:
 +      kfree(md->ima.active_table.device_metadata);
 +
 +      if (md->ima.active_table.device_metadata !=
 +          md->ima.inactive_table.device_metadata)
 +              kfree(md->ima.inactive_table.device_metadata);
 +
 +      kfree(md->ima.active_table.hash);
 +
 +      if (md->ima.active_table.hash != md->ima.inactive_table.hash)
 +              kfree(md->ima.inactive_table.hash);
 +
 +      dm_ima_reset_data(md);
 +
 +      kfree(dev_name);
 +      kfree(dev_uuid);
 +}
 +
 +/*
 + * Measure ima data on table clear.
 + */
 +void dm_ima_measure_on_table_clear(struct mapped_device *md, bool new_map)
 +{
 +      unsigned int l = 0, capacity_len = 0;
 +      char *device_table_data = NULL, *dev_name = NULL, *dev_uuid = NULL, *capacity_str = NULL;
 +      char inactive_str[] = "inactive_table_hash=";
 +      unsigned int inactive_len = strlen(inactive_str);
 +      bool noio = true;
 +      bool nodata = true;
 +      int r;
 +
 +      device_table_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN, GFP_KERNEL, noio);
 +      if (!device_table_data)
 +              return;
 +
 +      r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
 +      if (r)
 +              goto error1;
 +
 +      memcpy(device_table_data + l, DM_IMA_VERSION_STR, md->ima.dm_version_str_len);
 +      l += md->ima.dm_version_str_len;
 +
 +      if (md->ima.inactive_table.device_metadata_len &&
 +          md->ima.inactive_table.hash_len) {
 +              memcpy(device_table_data + l, md->ima.inactive_table.device_metadata,
 +                     md->ima.inactive_table.device_metadata_len);
 +              l += md->ima.inactive_table.device_metadata_len;
 +
 +              memcpy(device_table_data + l, inactive_str, inactive_len);
 +              l += inactive_len;
 +
 +              memcpy(device_table_data + l, md->ima.inactive_table.hash,
 +                         md->ima.inactive_table.hash_len);
 +
 +              l += md->ima.inactive_table.hash_len;
 +
 +              memcpy(device_table_data + l, ";", 1);
 +              l++;
 +
 +              nodata = false;
 +      }
 +
 +      if (nodata) {
 +              if (dm_ima_alloc_and_copy_name_uuid(md, &dev_name, &dev_uuid, noio))
 +                      goto error2;
 +
 +              scnprintf(device_table_data, DM_IMA_DEVICE_BUF_LEN,
 +                        "%sname=%s,uuid=%s;table_clear=no_data;",
 +                         DM_IMA_VERSION_STR, dev_name, dev_uuid);
 +              l += strlen(device_table_data);
 +      }
 +
 +      capacity_len = strlen(capacity_str);
 +      memcpy(device_table_data + l, capacity_str, capacity_len);
 +      l += capacity_len;
 +
 +      dm_ima_measure_data("dm_table_clear", device_table_data, l, noio);
 +
 +      if (new_map) {
 +              if (md->ima.inactive_table.hash &&
 +                  md->ima.inactive_table.hash != md->ima.active_table.hash)
 +                      kfree(md->ima.inactive_table.hash);
 +
 +              md->ima.inactive_table.hash = NULL;
 +              md->ima.inactive_table.hash_len = 0;
 +
 +              if (md->ima.inactive_table.device_metadata &&
 +                  md->ima.inactive_table.device_metadata != md->ima.active_table.device_metadata)
 +                      kfree(md->ima.inactive_table.device_metadata);
 +
 +              md->ima.inactive_table.device_metadata = NULL;
 +              md->ima.inactive_table.device_metadata_len = 0;
 +              md->ima.inactive_table.num_targets = 0;
 +
 +              if (md->ima.active_table.hash) {
 +                      md->ima.inactive_table.hash = md->ima.active_table.hash;
 +                      md->ima.inactive_table.hash_len = md->ima.active_table.hash_len;
 +              }
 +
 +              if (md->ima.active_table.device_metadata) {
 +                      md->ima.inactive_table.device_metadata =
 +                              md->ima.active_table.device_metadata;
 +                      md->ima.inactive_table.device_metadata_len =
 +                              md->ima.active_table.device_metadata_len;
 +                      md->ima.inactive_table.num_targets =
 +                              md->ima.active_table.num_targets;
 +              }
 +      }
 +
 +      kfree(dev_name);
 +      kfree(dev_uuid);
 +error2:
 +      kfree(capacity_str);
 +error1:
 +      kfree(device_table_data);
 +}
 +
 +/*
 + * Measure IMA data on device rename.
 + */
 +void dm_ima_measure_on_device_rename(struct mapped_device *md)
 +{
 +      char *old_device_data = NULL, *new_device_data = NULL, *combined_device_data = NULL;
 +      char *new_dev_name = NULL, *new_dev_uuid = NULL, *capacity_str = NULL;
 +      bool noio = true;
 +      int r;
 +
 +      if (dm_ima_alloc_and_copy_device_data(md, &new_device_data,
 +                                            md->ima.active_table.num_targets, noio))
 +              return;
 +
 +      if (dm_ima_alloc_and_copy_name_uuid(md, &new_dev_name, &new_dev_uuid, noio))
 +              goto error;
 +
 +      combined_device_data = dm_ima_alloc(DM_IMA_DEVICE_BUF_LEN * 2, GFP_KERNEL, noio);
 +      if (!combined_device_data)
 +              goto error;
 +
 +      r = dm_ima_alloc_and_copy_capacity_str(md, &capacity_str, noio);
 +      if (r)
 +              goto error;
 +
 +      old_device_data = md->ima.active_table.device_metadata;
 +
 +      md->ima.active_table.device_metadata = new_device_data;
 +      md->ima.active_table.device_metadata_len = strlen(new_device_data);
 +
 +      scnprintf(combined_device_data, DM_IMA_DEVICE_BUF_LEN * 2,
 +                "%s%snew_name=%s,new_uuid=%s;%s", DM_IMA_VERSION_STR, old_device_data,
 +                new_dev_name, new_dev_uuid, capacity_str);
 +
 +      dm_ima_measure_data("dm_device_rename", combined_device_data, strlen(combined_device_data),
 +                          noio);
 +
 +      goto exit;
 +
 +error:
 +      kfree(new_device_data);
 +exit:
 +      kfree(capacity_str);
 +      kfree(combined_device_data);
 +      kfree(old_device_data);
 +      kfree(new_dev_name);
 +      kfree(new_dev_uuid);
 +}
index 673833f940694fa4e43a2ab6d57638cea7cb63c3,a734f7d5292c2644e2edaadd729e744c364af54e..465865412100bf656038ce151c6f60006cf3a382
@@@ -972,20 -1006,24 +1006,25 @@@ void ima_kexec_cmdline(int kernel_fd, c
   * and extend the pcr.  Examples of critical data could be various data
   * structures, policies, and states stored in kernel memory that can
   * impact the integrity of the system.
+  *
+  * Return: 0 if the buffer has been successfully measured, 1 if the digest
+  * has been written to the passed location but not added to a measurement entry,
+  * a negative value otherwise.
   */
void ima_measure_critical_data(const char *event_label,
-                              const char *event_name,
-                              const void *buf, size_t buf_len,
-                              bool hash)
int ima_measure_critical_data(const char *event_label,
+                             const char *event_name,
+                             const void *buf, size_t buf_len,
+                             bool hash, u8 *digest, size_t digest_len)
  {
        if (!event_name || !event_label || !buf || !buf_len)
-               return;
+               return -ENOPARAM;
  
-       process_buffer_measurement(&init_user_ns, NULL, buf, buf_len, event_name,
-                                  CRITICAL_DATA, 0, event_label,
-                                  hash);
+       return process_buffer_measurement(&init_user_ns, NULL, buf, buf_len,
+                                         event_name, CRITICAL_DATA, 0,
+                                         event_label, hash, digest,
+                                         digest_len);
  }
 +EXPORT_SYMBOL_GPL(ima_measure_critical_data);
  
  static int __init init_ima(void)
  {