From 0f34a0060aebf202010b3f8fef348653a2df2346 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 24 Sep 2014 11:05:10 +0300 Subject: ima: check ima_policy_flag in the ima_file_free() hook This patch completes the switching to the 'ima_policy_flag' variable in the checks at the beginning of IMA functions, starting with the commit a756024e. Checking 'iint_initialized' is completely unnecessary, because S_IMA flag is unset if iint was not allocated. At the same time the integrity cache is allocated with SLAB_PANIC and the kernel will panic if the allocation fails during kernel initialization. So on a running system iint_initialized is always true and can be removed. Changes in v3: * not limiting test to IMA_APPRAISE (spotted by Roberto Sassu) Changes in v2: * 'iint_initialized' removal patch merged to this patch (requested by Mimi) Signed-off-by: Dmitry Kasatkin Acked-by: Roberto Sassu --- security/integrity/integrity.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'security/integrity/integrity.h') diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index c0379d13dbe1..883a5fc75449 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -169,6 +169,3 @@ static inline void integrity_audit_msg(int audit_msgno, struct inode *inode, { } #endif - -/* set during initialization */ -extern int iint_initialized; -- cgit v1.2.3 From d16a8585d3715ef161cc9858b50ea5d3c8b6079b Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 1 Oct 2014 21:43:07 +0300 Subject: integrity: add missing '__init' keyword for integrity_init_keyring() integrity_init_keyring() is used only from kernel '__init' functions. Add it there as well. Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/digsig.c | 2 +- security/integrity/integrity.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'security/integrity/integrity.h') diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 8d4fbff8b87c..4f643d1b34dd 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -63,7 +63,7 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, return -EOPNOTSUPP; } -int integrity_init_keyring(const unsigned int id) +int __init integrity_init_keyring(const unsigned int id) { const struct cred *cred = current_cred(); int err = 0; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 883a5fc75449..f51ad65c894d 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -129,7 +129,7 @@ struct integrity_iint_cache *integrity_iint_find(struct inode *inode); int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, const char *digest, int digestlen); -int integrity_init_keyring(const unsigned int id); +int __init integrity_init_keyring(const unsigned int id); #else static inline int integrity_digsig_verify(const unsigned int id, -- cgit v1.2.3 From e3c4abbfa97ed0b7aed36f18b32911ccf76d52c2 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 5 Nov 2014 17:01:12 +0200 Subject: integrity: define a new function integrity_read_file() This patch defines a new function called integrity_read_file() to read file from the kernel into a buffer. Subsequent patches will read a file containing the public keys and load them onto the IMA keyring. This patch moves and renames ima_kernel_read(), the non-security checking version of kernel_read(), to integrity_kernel_read(). Changes in v3: * Patch descriptions improved (Mimi) * Add missing cast (kbuild test robot) Changes in v2: * configuration option removed * function declared as '__init' Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/iint.c | 78 +++++++++++++++++++++++++++++++++++++ security/integrity/ima/ima_crypto.c | 35 ++--------------- security/integrity/integrity.h | 4 ++ 3 files changed, 85 insertions(+), 32 deletions(-) (limited to 'security/integrity/integrity.h') diff --git a/security/integrity/iint.c b/security/integrity/iint.c index cc3eb4de18a1..dbee618526b6 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -19,6 +19,8 @@ #include #include #include +#include +#include #include "integrity.h" static struct rb_root integrity_iint_tree = RB_ROOT; @@ -167,3 +169,79 @@ static int __init integrity_iintcache_init(void) return 0; } security_initcall(integrity_iintcache_init); + + +/* + * integrity_kernel_read - read data from the file + * + * This is a function for reading file content instead of kernel_read(). + * It does not perform locking checks to ensure it cannot be blocked. + * It does not perform security checks because it is irrelevant for IMA. + * + */ +int integrity_kernel_read(struct file *file, loff_t offset, + char *addr, unsigned long count) +{ + mm_segment_t old_fs; + char __user *buf = (char __user *)addr; + ssize_t ret = -EINVAL; + + if (!(file->f_mode & FMODE_READ)) + return -EBADF; + + old_fs = get_fs(); + set_fs(get_ds()); + if (file->f_op->read) + ret = file->f_op->read(file, buf, count, &offset); + else if (file->f_op->aio_read) + ret = do_sync_read(file, buf, count, &offset); + else if (file->f_op->read_iter) + ret = new_sync_read(file, buf, count, &offset); + set_fs(old_fs); + return ret; +} + +/* + * integrity_read_file - read entire file content into the buffer + * + * This is function opens a file, allocates the buffer of required + * size, read entire file content to the buffer and closes the file + * + * It is used only by init code. + * + */ +int __init integrity_read_file(const char *path, char **data) +{ + struct file *file; + loff_t size; + char *buf; + int rc = -EINVAL; + + file = filp_open(path, O_RDONLY, 0); + if (IS_ERR(file)) { + rc = PTR_ERR(file); + pr_err("Unable to open file: %s (%d)", path, rc); + return rc; + } + + size = i_size_read(file_inode(file)); + if (size <= 0) + goto out; + + buf = kmalloc(size, GFP_KERNEL); + if (!buf) { + rc = -ENOMEM; + goto out; + } + + rc = integrity_kernel_read(file, 0, buf, size); + if (rc < 0) + kfree(buf); + else if (rc != size) + rc = -EIO; + else + *data = buf; +out: + fput(file); + return rc; +} diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index d34e7dfc1118..5df4d960d4dc 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -67,36 +67,6 @@ MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); static struct crypto_shash *ima_shash_tfm; static struct crypto_ahash *ima_ahash_tfm; -/** - * ima_kernel_read - read file content - * - * This is a function for reading file content instead of kernel_read(). - * It does not perform locking checks to ensure it cannot be blocked. - * It does not perform security checks because it is irrelevant for IMA. - * - */ -static int ima_kernel_read(struct file *file, loff_t offset, - char *addr, unsigned long count) -{ - mm_segment_t old_fs; - char __user *buf = addr; - ssize_t ret = -EINVAL; - - if (!(file->f_mode & FMODE_READ)) - return -EBADF; - - old_fs = get_fs(); - set_fs(get_ds()); - if (file->f_op->read) - ret = file->f_op->read(file, buf, count, &offset); - else if (file->f_op->aio_read) - ret = do_sync_read(file, buf, count, &offset); - else if (file->f_op->read_iter) - ret = new_sync_read(file, buf, count, &offset); - set_fs(old_fs); - return ret; -} - int __init ima_init_crypto(void) { long rc; @@ -324,7 +294,8 @@ static int ima_calc_file_hash_atfm(struct file *file, } /* read buffer */ rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]); - rc = ima_kernel_read(file, offset, rbuf[active], rbuf_len); + rc = integrity_kernel_read(file, offset, rbuf[active], + rbuf_len); if (rc != rbuf_len) goto out3; @@ -417,7 +388,7 @@ static int ima_calc_file_hash_tfm(struct file *file, while (offset < i_size) { int rbuf_len; - rbuf_len = ima_kernel_read(file, offset, rbuf, PAGE_SIZE); + rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE); if (rbuf_len < 0) { rc = rbuf_len; break; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index f51ad65c894d..20d220481025 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -119,6 +119,10 @@ struct integrity_iint_cache { */ struct integrity_iint_cache *integrity_iint_find(struct inode *inode); +int integrity_kernel_read(struct file *file, loff_t offset, + char *addr, unsigned long count); +int __init integrity_read_file(const char *path, char **data); + #define INTEGRITY_KEYRING_EVM 0 #define INTEGRITY_KEYRING_MODULE 1 #define INTEGRITY_KEYRING_IMA 2 -- cgit v1.2.3 From 65d543b2335ede80e5e66bc4f559f62db5f469bd Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 5 Nov 2014 17:01:13 +0200 Subject: integrity: provide a function to load x509 certificate from the kernel Provide the function to load x509 certificates from the kernel into the integrity kernel keyring. Changes in v2: * configuration option removed * function declared as '__init' Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/digsig.c | 36 +++++++++++++++++++++++++++++++++++- security/integrity/integrity.h | 2 ++ 2 files changed, 37 insertions(+), 1 deletion(-) (limited to 'security/integrity/integrity.h') diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 4f643d1b34dd..5e3bd72b299a 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -14,7 +14,7 @@ #include #include -#include +#include #include #include #include @@ -84,3 +84,37 @@ int __init integrity_init_keyring(const unsigned int id) } return err; } + +int __init integrity_load_x509(const unsigned int id, char *path) +{ + key_ref_t key; + char *data; + int rc; + + if (!keyring[id]) + return -EINVAL; + + rc = integrity_read_file(path, &data); + if (rc < 0) + return rc; + + key = key_create_or_update(make_key_ref(keyring[id], 1), + "asymmetric", + NULL, + data, + rc, + ((KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ), + KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_TRUSTED); + if (IS_ERR(key)) { + rc = PTR_ERR(key); + pr_err("Problem loading X.509 certificate (%d): %s\n", + rc, path); + } else { + pr_notice("Loaded X.509 cert '%s': %s\n", + key_ref_to_ptr(key)->description, path); + key_ref_put(key); + } + kfree(data); + return 0; +} diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 20d220481025..1057abbd31cd 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -134,6 +134,7 @@ int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen, const char *digest, int digestlen); int __init integrity_init_keyring(const unsigned int id); +int __init integrity_load_x509(const unsigned int id, char *path); #else static inline int integrity_digsig_verify(const unsigned int id, @@ -147,6 +148,7 @@ static inline int integrity_init_keyring(const unsigned int id) { return 0; } + #endif /* CONFIG_INTEGRITY_SIGNATURE */ #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS -- cgit v1.2.3 From fd5f4e9054acbf4f22fac81a358baf3c27aa42ac Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 5 Nov 2014 17:01:14 +0200 Subject: ima: load x509 certificate from the kernel Define configuration option to load X509 certificate into the IMA trusted kernel keyring. It implements ima_load_x509() hook to load X509 certificate into the .ima trusted kernel keyring from the root filesystem. Changes in v3: * use ima_policy_flag in ima_get_action() ima_load_x509 temporarily clears ima_policy_flag to disable appraisal to load key. Use it to skip appraisal rules. * Key directory path changed to /etc/keys (Mimi) * Expand IMA_LOAD_X509 Kconfig help Changes in v2: * added '__init' * use ima_policy_flag to disable appraisal to load keys Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- security/integrity/ima/Kconfig | 18 ++++++++++++++++++ security/integrity/ima/ima_api.c | 3 +-- security/integrity/ima/ima_init.c | 17 +++++++++++++++++ security/integrity/integrity.h | 8 ++++++++ 4 files changed, 44 insertions(+), 2 deletions(-) (limited to 'security/integrity/integrity.h') diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index e099875643c5..b0840f9a552f 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -131,3 +131,21 @@ config IMA_TRUSTED_KEYRING help This option requires that all keys added to the .ima keyring be signed by a key on the system trusted keyring. + +config IMA_LOAD_X509 + bool "Load X509 certificate onto the '.ima' trusted keyring" + depends on IMA_TRUSTED_KEYRING + default n + help + File signature verification is based on the public keys + loaded on the .ima trusted keyring. These public keys are + X509 certificates signed by a trusted key on the + .system keyring. This option enables X509 certificate + loading from the kernel onto the '.ima' trusted keyring. + +config IMA_X509_PATH + string "IMA X509 certificate path" + depends on IMA_LOAD_X509 + default "/etc/keys/x509_ima.der" + help + This option defines IMA X509 certificate path. diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index a99eb6d4bc09..b0dc922d8be3 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -173,8 +173,7 @@ int ima_get_action(struct inode *inode, int mask, int function) { int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE; - if (!ima_appraise) - flags &= ~IMA_APPRAISE; + flags &= ima_policy_flag; return ima_match_policy(inode, function, mask, flags); } diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 9164fc8cac84..5e4c29d174ee 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -24,6 +24,12 @@ #include #include "ima.h" +#ifdef CONFIG_IMA_X509_PATH +#define IMA_X509_PATH CONFIG_IMA_X509_PATH +#else +#define IMA_X509_PATH "/etc/keys/x509_ima.der" +#endif + /* name for boot aggregate entry */ static const char *boot_aggregate_name = "boot_aggregate"; int ima_used_chip; @@ -91,6 +97,17 @@ err_out: return result; } +#ifdef CONFIG_IMA_LOAD_X509 +void __init ima_load_x509(void) +{ + int unset_flags = ima_policy_flag & IMA_APPRAISE; + + ima_policy_flag &= ~unset_flags; + integrity_load_x509(INTEGRITY_KEYRING_IMA, IMA_X509_PATH); + ima_policy_flag |= unset_flags; +} +#endif + int __init ima_init(void) { u8 pcr_i[TPM_DIGEST_SIZE]; diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 1057abbd31cd..caa1f6ca72e9 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -162,6 +162,14 @@ static inline int asymmetric_verify(struct key *keyring, const char *sig, } #endif +#ifdef CONFIG_IMA_LOAD_X509 +void __init ima_load_x509(void); +#else +static inline void ima_load_x509(void) +{ +} +#endif + #ifdef CONFIG_INTEGRITY_AUDIT /* declarations */ void integrity_audit_msg(int audit_msgno, struct inode *inode, -- cgit v1.2.3