diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-03 08:50:52 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-03 08:50:52 -0700 |
commit | 0302e28dee643932ee7b3c112ebccdbb9f8ec32c (patch) | |
tree | 405d4cb3f772ef069ed7f291adc4b74a4e73346e /drivers/char/tpm/tpm2-space.c | |
parent | 89c9fea3c8034cdb2fd745f551cde0b507fd6893 (diff) | |
parent | 8979b02aaf1d6de8d52cc143aa4da961ed32e5a2 (diff) |
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
"Highlights:
IMA:
- provide ">" and "<" operators for fowner/uid/euid rules
KEYS:
- add a system blacklist keyring
- add KEYCTL_RESTRICT_KEYRING, exposes keyring link restriction
functionality to userland via keyctl()
LSM:
- harden LSM API with __ro_after_init
- add prlmit security hook, implement for SELinux
- revive security_task_alloc hook
TPM:
- implement contextual TPM command 'spaces'"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (98 commits)
tpm: Fix reference count to main device
tpm_tis: convert to using locality callbacks
tpm: fix handling of the TPM 2.0 event logs
tpm_crb: remove a cruft constant
keys: select CONFIG_CRYPTO when selecting DH / KDF
apparmor: Make path_max parameter readonly
apparmor: fix parameters so that the permission test is bypassed at boot
apparmor: fix invalid reference to index variable of iterator line 836
apparmor: use SHASH_DESC_ON_STACK
security/apparmor/lsm.c: set debug messages
apparmor: fix boolreturn.cocci warnings
Smack: Use GFP_KERNEL for smk_netlbl_mls().
smack: fix double free in smack_parse_opts_str()
KEYS: add SP800-56A KDF support for DH
KEYS: Keyring asymmetric key restrict method with chaining
KEYS: Restrict asymmetric key linkage using a specific keychain
KEYS: Add a lookup_restriction function for the asymmetric key type
KEYS: Add KEYCTL_RESTRICT_KEYRING
KEYS: Consistent ordering for __key_link_begin and restrict check
KEYS: Add an optional lookup_restriction hook to key_type
...
Diffstat (limited to 'drivers/char/tpm/tpm2-space.c')
-rw-r--r-- | drivers/char/tpm/tpm2-space.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c new file mode 100644 index 000000000000..e2e059d8ffec --- /dev/null +++ b/drivers/char/tpm/tpm2-space.c @@ -0,0 +1,528 @@ +/* + * Copyright (C) 2016 Intel Corporation + * + * Authors: + * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> + * + * Maintained by: <tpmdd-devel@lists.sourceforge.net> + * + * This file contains TPM2 protocol implementations of the commands + * used by the kernel internally. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <linux/gfp.h> +#include <asm/unaligned.h> +#include "tpm.h" + +enum tpm2_handle_types { + TPM2_HT_HMAC_SESSION = 0x02000000, + TPM2_HT_POLICY_SESSION = 0x03000000, + TPM2_HT_TRANSIENT = 0x80000000, +}; + +struct tpm2_context { + __be64 sequence; + __be32 saved_handle; + __be32 hierarchy; + __be16 blob_size; +} __packed; + +static void tpm2_flush_sessions(struct tpm_chip *chip, struct tpm_space *space) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) { + if (space->session_tbl[i]) + tpm2_flush_context_cmd(chip, space->session_tbl[i], + TPM_TRANSMIT_UNLOCKED); + } +} + +int tpm2_init_space(struct tpm_space *space) +{ + space->context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!space->context_buf) + return -ENOMEM; + + space->session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (space->session_buf == NULL) { + kfree(space->context_buf); + return -ENOMEM; + } + + return 0; +} + +void tpm2_del_space(struct tpm_chip *chip, struct tpm_space *space) +{ + mutex_lock(&chip->tpm_mutex); + tpm2_flush_sessions(chip, space); + mutex_unlock(&chip->tpm_mutex); + kfree(space->context_buf); + kfree(space->session_buf); +} + +static int tpm2_load_context(struct tpm_chip *chip, u8 *buf, + unsigned int *offset, u32 *handle) +{ + struct tpm_buf tbuf; + struct tpm2_context *ctx; + unsigned int body_size; + int rc; + + rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_LOAD); + if (rc) + return rc; + + ctx = (struct tpm2_context *)&buf[*offset]; + body_size = sizeof(*ctx) + be16_to_cpu(ctx->blob_size); + tpm_buf_append(&tbuf, &buf[*offset], body_size); + + rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 4, + TPM_TRANSMIT_UNLOCKED, NULL); + if (rc < 0) { + dev_warn(&chip->dev, "%s: failed with a system error %d\n", + __func__, rc); + tpm_buf_destroy(&tbuf); + return -EFAULT; + } else if (tpm2_rc_value(rc) == TPM2_RC_HANDLE || + rc == TPM2_RC_REFERENCE_H0) { + /* + * TPM_RC_HANDLE means that the session context can't + * be loaded because of an internal counter mismatch + * that makes the TPM think there might have been a + * replay. This might happen if the context was saved + * and loaded outside the space. + * + * TPM_RC_REFERENCE_H0 means the session has been + * flushed outside the space + */ + rc = -ENOENT; + tpm_buf_destroy(&tbuf); + } else if (rc > 0) { + dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n", + __func__, rc); + tpm_buf_destroy(&tbuf); + return -EFAULT; + } + + *handle = be32_to_cpup((__be32 *)&tbuf.data[TPM_HEADER_SIZE]); + *offset += body_size; + + tpm_buf_destroy(&tbuf); + return 0; +} + +static int tpm2_save_context(struct tpm_chip *chip, u32 handle, u8 *buf, + unsigned int buf_size, unsigned int *offset) +{ + struct tpm_buf tbuf; + unsigned int body_size; + int rc; + + rc = tpm_buf_init(&tbuf, TPM2_ST_NO_SESSIONS, TPM2_CC_CONTEXT_SAVE); + if (rc) + return rc; + + tpm_buf_append_u32(&tbuf, handle); + + rc = tpm_transmit_cmd(chip, NULL, tbuf.data, PAGE_SIZE, 0, + TPM_TRANSMIT_UNLOCKED, NULL); + if (rc < 0) { + dev_warn(&chip->dev, "%s: failed with a system error %d\n", + __func__, rc); + tpm_buf_destroy(&tbuf); + return -EFAULT; + } else if (tpm2_rc_value(rc) == TPM2_RC_REFERENCE_H0) { + tpm_buf_destroy(&tbuf); + return -ENOENT; + } else if (rc) { + dev_warn(&chip->dev, "%s: failed with a TPM error 0x%04X\n", + __func__, rc); + tpm_buf_destroy(&tbuf); + return -EFAULT; + } + + body_size = tpm_buf_length(&tbuf) - TPM_HEADER_SIZE; + if ((*offset + body_size) > buf_size) { + dev_warn(&chip->dev, "%s: out of backing storage\n", __func__); + tpm_buf_destroy(&tbuf); + return -ENOMEM; + } + + memcpy(&buf[*offset], &tbuf.data[TPM_HEADER_SIZE], body_size); + *offset += body_size; + tpm_buf_destroy(&tbuf); + return 0; +} + +static void tpm2_flush_space(struct tpm_chip *chip) +{ + struct tpm_space *space = &chip->work_space; + int i; + + for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) + if (space->context_tbl[i] && ~space->context_tbl[i]) + tpm2_flush_context_cmd(chip, space->context_tbl[i], + TPM_TRANSMIT_UNLOCKED); + + tpm2_flush_sessions(chip, space); +} + +static int tpm2_load_space(struct tpm_chip *chip) +{ + struct tpm_space *space = &chip->work_space; + unsigned int offset; + int i; + int rc; + + for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) { + if (!space->context_tbl[i]) + continue; + + /* sanity check, should never happen */ + if (~space->context_tbl[i]) { + dev_err(&chip->dev, "context table is inconsistent"); + return -EFAULT; + } + + rc = tpm2_load_context(chip, space->context_buf, &offset, + &space->context_tbl[i]); + if (rc) + return rc; + } + + for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) { + u32 handle; + + if (!space->session_tbl[i]) + continue; + + rc = tpm2_load_context(chip, space->session_buf, + &offset, &handle); + if (rc == -ENOENT) { + /* load failed, just forget session */ + space->session_tbl[i] = 0; + } else if (rc) { + tpm2_flush_space(chip); + return rc; + } + if (handle != space->session_tbl[i]) { + dev_warn(&chip->dev, "session restored to wrong handle\n"); + tpm2_flush_space(chip); + return -EFAULT; + } + } + + return 0; +} + +static bool tpm2_map_to_phandle(struct tpm_space *space, void *handle) +{ + u32 vhandle = be32_to_cpup((__be32 *)handle); + u32 phandle; + int i; + + i = 0xFFFFFF - (vhandle & 0xFFFFFF); + if (i >= ARRAY_SIZE(space->context_tbl) || !space->context_tbl[i]) + return false; + + phandle = space->context_tbl[i]; + *((__be32 *)handle) = cpu_to_be32(phandle); + return true; +} + +static int tpm2_map_command(struct tpm_chip *chip, u32 cc, u8 *cmd) +{ + struct tpm_space *space = &chip->work_space; + unsigned int nr_handles; + u32 attrs; + u32 *handle; + int i; + + i = tpm2_find_cc(chip, cc); + if (i < 0) + return -EINVAL; + + attrs = chip->cc_attrs_tbl[i]; + nr_handles = (attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0); + + handle = (u32 *)&cmd[TPM_HEADER_SIZE]; + for (i = 0; i < nr_handles; i++, handle++) { + if ((be32_to_cpu(*handle) & 0xFF000000) == TPM2_HT_TRANSIENT) { + if (!tpm2_map_to_phandle(space, handle)) + return -EINVAL; + } + } + + return 0; +} + +int tpm2_prepare_space(struct tpm_chip *chip, struct tpm_space *space, u32 cc, + u8 *cmd) +{ + int rc; + + if (!space) + return 0; + + memcpy(&chip->work_space.context_tbl, &space->context_tbl, + sizeof(space->context_tbl)); + memcpy(&chip->work_space.session_tbl, &space->session_tbl, + sizeof(space->session_tbl)); + memcpy(chip->work_space.context_buf, space->context_buf, PAGE_SIZE); + memcpy(chip->work_space.session_buf, space->session_buf, PAGE_SIZE); + + rc = tpm2_load_space(chip); + if (rc) { + tpm2_flush_space(chip); + return rc; + } + + rc = tpm2_map_command(chip, cc, cmd); + if (rc) { + tpm2_flush_space(chip); + return rc; + } + + return 0; +} + +static bool tpm2_add_session(struct tpm_chip *chip, u32 handle) +{ + struct tpm_space *space = &chip->work_space; + int i; + + for (i = 0; i < ARRAY_SIZE(space->session_tbl); i++) + if (space->session_tbl[i] == 0) + break; + + if (i == ARRAY_SIZE(space->session_tbl)) + return false; + + space->session_tbl[i] = handle; + return true; +} + +static u32 tpm2_map_to_vhandle(struct tpm_space *space, u32 phandle, bool alloc) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++) { + if (alloc) { + if (!space->context_tbl[i]) { + space->context_tbl[i] = phandle; + break; + } + } else if (space->context_tbl[i] == phandle) + break; + } + + if (i == ARRAY_SIZE(space->context_tbl)) + return 0; + + return TPM2_HT_TRANSIENT | (0xFFFFFF - i); +} + +static int tpm2_map_response_header(struct tpm_chip *chip, u32 cc, u8 *rsp, + size_t len) +{ + struct tpm_space *space = &chip->work_space; + struct tpm_output_header *header = (void *)rsp; + u32 phandle; + u32 phandle_type; + u32 vhandle; + u32 attrs; + int i; + + if (be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS) + return 0; + + i = tpm2_find_cc(chip, cc); + /* sanity check, should never happen */ + if (i < 0) + return -EFAULT; + + attrs = chip->cc_attrs_tbl[i]; + if (!((attrs >> TPM2_CC_ATTR_RHANDLE) & 1)) + return 0; + + phandle = be32_to_cpup((__be32 *)&rsp[TPM_HEADER_SIZE]); + phandle_type = phandle & 0xFF000000; + + switch (phandle_type) { + case TPM2_HT_TRANSIENT: + vhandle = tpm2_map_to_vhandle(space, phandle, true); + if (!vhandle) + goto out_no_slots; + + *(__be32 *)&rsp[TPM_HEADER_SIZE] = cpu_to_be32(vhandle); + break; + case TPM2_HT_HMAC_SESSION: + case TPM2_HT_POLICY_SESSION: + if (!tpm2_add_session(chip, phandle)) + goto out_no_slots; + break; + default: + dev_err(&chip->dev, "%s: unknown handle 0x%08X\n", + __func__, phandle); + break; + }; + + return 0; +out_no_slots: + tpm2_flush_context_cmd(chip, phandle, TPM_TRANSMIT_UNLOCKED); + dev_warn(&chip->dev, "%s: out of slots for 0x%08X\n", __func__, + phandle); + return -ENOMEM; +} + +struct tpm2_cap_handles { + u8 more_data; + __be32 capability; + __be32 count; + __be32 handles[]; +} __packed; + +static int tpm2_map_response_body(struct tpm_chip *chip, u32 cc, u8 *rsp, + size_t len) +{ + struct tpm_space *space = &chip->work_space; + struct tpm_output_header *header = (void *)rsp; + struct tpm2_cap_handles *data; + u32 phandle; + u32 phandle_type; + u32 vhandle; + int i; + int j; + + if (cc != TPM2_CC_GET_CAPABILITY || + be32_to_cpu(header->return_code) != TPM2_RC_SUCCESS) { + return 0; + } + + if (len < TPM_HEADER_SIZE + 9) + return -EFAULT; + + data = (void *)&rsp[TPM_HEADER_SIZE]; + if (be32_to_cpu(data->capability) != TPM2_CAP_HANDLES) + return 0; + + if (len != TPM_HEADER_SIZE + 9 + 4 * be32_to_cpu(data->count)) + return -EFAULT; + + for (i = 0, j = 0; i < be32_to_cpu(data->count); i++) { + phandle = be32_to_cpup((__be32 *)&data->handles[i]); + phandle_type = phandle & 0xFF000000; + + switch (phandle_type) { + case TPM2_HT_TRANSIENT: + vhandle = tpm2_map_to_vhandle(space, phandle, false); + if (!vhandle) + break; + + data->handles[j] = cpu_to_be32(vhandle); + j++; + break; + + default: + data->handles[j] = cpu_to_be32(phandle); + j++; + break; + } + + } + + header->length = cpu_to_be32(TPM_HEADER_SIZE + 9 + 4 * j); + data->count = cpu_to_be32(j); + return 0; +} + +static int tpm2_save_space(struct tpm_chip *chip) +{ + struct tpm_space *space = &chip->work_space; + unsigned int offset; + int i; + int rc; + + for (i = 0, offset = 0; i < ARRAY_SIZE(space->context_tbl); i++) { + if (!(space->context_tbl[i] && ~space->context_tbl[i])) + continue; + + rc = tpm2_save_context(chip, space->context_tbl[i], + space->context_buf, PAGE_SIZE, + &offset); + if (rc == -ENOENT) { + space->context_tbl[i] = 0; + continue; + } else if (rc) + return rc; + + tpm2_flush_context_cmd(chip, space->context_tbl[i], + TPM_TRANSMIT_UNLOCKED); + space->context_tbl[i] = ~0; + } + + for (i = 0, offset = 0; i < ARRAY_SIZE(space->session_tbl); i++) { + if (!space->session_tbl[i]) + continue; + + rc = tpm2_save_context(chip, space->session_tbl[i], + space->session_buf, PAGE_SIZE, + &offset); + + if (rc == -ENOENT) { + /* handle error saving session, just forget it */ + space->session_tbl[i] = 0; + } else if (rc < 0) { + tpm2_flush_space(chip); + return rc; + } + } + + return 0; +} + +int tpm2_commit_space(struct tpm_chip *chip, struct tpm_space *space, + u32 cc, u8 *buf, size_t *bufsiz) +{ + struct tpm_output_header *header = (void *)buf; + int rc; + + if (!space) + return 0; + + rc = tpm2_map_response_header(chip, cc, buf, *bufsiz); + if (rc) { + tpm2_flush_space(chip); + return rc; + } + + rc = tpm2_map_response_body(chip, cc, buf, *bufsiz); + if (rc) { + tpm2_flush_space(chip); + return rc; + } + + rc = tpm2_save_space(chip); + if (rc) { + tpm2_flush_space(chip); + return rc; + } + + *bufsiz = be32_to_cpu(header->length); + + memcpy(&space->context_tbl, &chip->work_space.context_tbl, + sizeof(space->context_tbl)); + memcpy(&space->session_tbl, &chip->work_space.session_tbl, + sizeof(space->session_tbl)); + memcpy(space->context_buf, chip->work_space.context_buf, PAGE_SIZE); + memcpy(space->session_buf, chip->work_space.session_buf, PAGE_SIZE); + + return 0; +} |