From 9f99798ff49e73dded73a8c674044ea6fb6af651 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Tue, 31 Jul 2012 20:37:00 +0900 Subject: ptrace: mark __ptrace_may_access() static __ptrace_may_access() is used within only kernel/ptrace.c. Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- include/linux/ptrace.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 597e4fdb97fe..3db698aee34c 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -130,8 +130,6 @@ extern void exit_ptrace(struct task_struct *tracer); #define PTRACE_MODE_READ 0x01 #define PTRACE_MODE_ATTACH 0x02 #define PTRACE_MODE_NOAUDIT 0x04 -/* Returns 0 on success, -errno on denial. */ -extern int __ptrace_may_access(struct task_struct *task, unsigned int mode); /* Returns true on success, false on denial. */ extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); -- cgit v1.3 From 41ab999c80f1d368f32a2554ba8f44feff26f54d Mon Sep 17 00:00:00 2001 From: Kent Yoder Date: Thu, 7 Jun 2012 13:47:14 -0500 Subject: tpm: Move tpm_get_random api into the TPM device driver Move the tpm_get_random api from the trusted keys code into the TPM device driver itself so that other callers can make use of it. Also, change the api slightly so that the number of bytes read is returned in the call, since the TPM command can potentially return fewer bytes than requested. Acked-by: David Safford Reviewed-by: H. Peter Anvin Signed-off-by: Kent Yoder --- drivers/char/tpm/tpm.c | 59 ++++++++++++++++++++++++++++++++++++++++++++----- drivers/char/tpm/tpm.h | 23 +++++++++++++++++++ include/linux/tpm.h | 4 ++++ security/keys/trusted.c | 54 ++++++++++---------------------------------- 4 files changed, 92 insertions(+), 48 deletions(-) (limited to 'include/linux') diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 677c6e26593f..36e43e50dcef 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -32,12 +32,6 @@ #include "tpm.h" #include "tpm_eventlog.h" -enum tpm_const { - TPM_MINOR = 224, /* officially assigned */ - TPM_BUFSIZE = 4096, - TPM_NUM_DEVICES = 256, -}; - enum tpm_duration { TPM_SHORT = 0, TPM_MEDIUM = 1, @@ -483,6 +477,7 @@ static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd, #define TPM_INTERNAL_RESULT_SIZE 200 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193) #define TPM_ORD_GET_CAP cpu_to_be32(101) +#define TPM_ORD_GET_RANDOM cpu_to_be32(70) static const struct tpm_input_header tpm_getcap_header = { .tag = TPM_TAG_RQU_COMMAND, @@ -1327,6 +1322,58 @@ int tpm_pm_resume(struct device *dev) } EXPORT_SYMBOL_GPL(tpm_pm_resume); +#define TPM_GETRANDOM_RESULT_SIZE 18 +static struct tpm_input_header tpm_getrandom_header = { + .tag = TPM_TAG_RQU_COMMAND, + .length = cpu_to_be32(14), + .ordinal = TPM_ORD_GET_RANDOM +}; + +/** + * tpm_get_random() - Get random bytes from the tpm's RNG + * @chip_num: A specific chip number for the request or TPM_ANY_NUM + * @out: destination buffer for the random bytes + * @max: the max number of bytes to write to @out + * + * Returns < 0 on error and the number of bytes read on success + */ +int tpm_get_random(u32 chip_num, u8 *out, size_t max) +{ + struct tpm_chip *chip; + struct tpm_cmd_t tpm_cmd; + u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA); + int err, total = 0, retries = 5; + u8 *dest = out; + + chip = tpm_chip_find_get(chip_num); + if (chip == NULL) + return -ENODEV; + + if (!out || !num_bytes || max > TPM_MAX_RNG_DATA) + return -EINVAL; + + do { + tpm_cmd.header.in = tpm_getrandom_header; + tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes); + + err = transmit_cmd(chip, &tpm_cmd, + TPM_GETRANDOM_RESULT_SIZE + num_bytes, + "attempting get random"); + if (err) + break; + + recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len); + memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd); + + dest += recd; + total += recd; + num_bytes -= recd; + } while (retries-- && total < max); + + return total ? total : -EIO; +} +EXPORT_SYMBOL_GPL(tpm_get_random); + /* In case vendor provided release function, call it too.*/ void tpm_dev_vendor_release(struct tpm_chip *chip) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 917f727e6740..645136eea890 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -28,6 +28,12 @@ #include #include +enum tpm_const { + TPM_MINOR = 224, /* officially assigned */ + TPM_BUFSIZE = 4096, + TPM_NUM_DEVICES = 256, +}; + enum tpm_timeout { TPM_TIMEOUT = 5, /* msecs */ }; @@ -269,6 +275,21 @@ struct tpm_pcrextend_in { u8 hash[TPM_DIGEST_SIZE]; }__attribute__((packed)); +/* 128 bytes is an arbitrary cap. This could be as large as TPM_BUFSIZE - 18 + * bytes, but 128 is still a relatively large number of random bytes and + * anything much bigger causes users of struct tpm_cmd_t to start getting + * compiler warnings about stack frame size. */ +#define TPM_MAX_RNG_DATA 128 + +struct tpm_getrandom_out { + __be32 rng_data_len; + u8 rng_data[TPM_MAX_RNG_DATA]; +}__attribute__((packed)); + +struct tpm_getrandom_in { + __be32 num_bytes; +}__attribute__((packed)); + typedef union { struct tpm_getcap_params_out getcap_out; struct tpm_readpubek_params_out readpubek_out; @@ -277,6 +298,8 @@ typedef union { struct tpm_pcrread_in pcrread_in; struct tpm_pcrread_out pcrread_out; struct tpm_pcrextend_in pcrextend_in; + struct tpm_getrandom_in getrandom_in; + struct tpm_getrandom_out getrandom_out; } tpm_cmd_params; struct tpm_cmd_t { diff --git a/include/linux/tpm.h b/include/linux/tpm.h index fdc718abf83b..fcb627ff8d3e 100644 --- a/include/linux/tpm.h +++ b/include/linux/tpm.h @@ -32,6 +32,7 @@ extern int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf); extern int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash); extern int tpm_send(u32 chip_num, void *cmd, size_t buflen); +extern int tpm_get_random(u32 chip_num, u8 *data, size_t max); #else static inline int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf) { return -ENODEV; @@ -42,5 +43,8 @@ static inline int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash) { static inline int tpm_send(u32 chip_num, void *cmd, size_t buflen) { return -ENODEV; } +static inline int tpm_get_random(u32 chip_num, u8 *data, size_t max) { + return -ENODEV; +} #endif #endif diff --git a/security/keys/trusted.c b/security/keys/trusted.c index 2d5d041f2049..3f163d0489ad 100644 --- a/security/keys/trusted.c +++ b/security/keys/trusted.c @@ -368,38 +368,6 @@ static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, return rc; } -/* - * get a random value from TPM - */ -static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) -{ - int ret; - - INIT_BUF(tb); - store16(tb, TPM_TAG_RQU_COMMAND); - store32(tb, TPM_GETRANDOM_SIZE); - store32(tb, TPM_ORD_GETRANDOM); - store32(tb, len); - ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); - if (!ret) - memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); - return ret; -} - -static int my_get_random(unsigned char *buf, int len) -{ - struct tpm_buf *tb; - int ret; - - tb = kmalloc(sizeof *tb, GFP_KERNEL); - if (!tb) - return -ENOMEM; - ret = tpm_get_random(tb, buf, len); - - kfree(tb); - return ret; -} - /* * Lock a trusted key, by extending a selected PCR. * @@ -413,8 +381,8 @@ static int pcrlock(const int pcrnum) if (!capable(CAP_SYS_ADMIN)) return -EPERM; - ret = my_get_random(hash, SHA1_DIGEST_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); + if (ret != SHA1_DIGEST_SIZE) return ret; return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; } @@ -429,8 +397,8 @@ static int osap(struct tpm_buf *tb, struct osapsess *s, unsigned char ononce[TPM_NONCE_SIZE]; int ret; - ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) return ret; INIT_BUF(tb); @@ -524,8 +492,8 @@ static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, if (ret < 0) goto out; - ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); - if (ret < 0) + ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) goto out; ordinal = htonl(TPM_ORD_SEAL); datsize = htonl(datalen); @@ -634,8 +602,8 @@ static int tpm_unseal(struct tpm_buf *tb, ordinal = htonl(TPM_ORD_UNSEAL); keyhndl = htonl(SRKHANDLE); - ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); - if (ret < 0) { + ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); + if (ret != TPM_NONCE_SIZE) { pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); return ret; } @@ -935,6 +903,7 @@ static int trusted_instantiate(struct key *key, const void *data, char *datablob; int ret = 0; int key_cmd; + size_t key_len; if (datalen <= 0 || datalen > 32767 || !data) return -EINVAL; @@ -974,8 +943,9 @@ static int trusted_instantiate(struct key *key, const void *data, pr_info("trusted_key: key_unseal failed (%d)\n", ret); break; case Opt_new: - ret = my_get_random(payload->key, payload->key_len); - if (ret < 0) { + key_len = payload->key_len; + ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); + if (ret != key_len) { pr_info("trusted_key: key_create failed (%d)\n", ret); goto out; } -- cgit v1.3 From c6993e4ac002c92bc75379212e9179c36d4bf7ee Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Tue, 4 Sep 2012 13:32:13 -0700 Subject: security: allow Yama to be unconditionally stacked Unconditionally call Yama when CONFIG_SECURITY_YAMA_STACKED is selected, no matter what LSM module is primary. Ubuntu and Chrome OS already carry patches to do this, and Fedora has voiced interest in doing this as well. Instead of having multiple distributions (or LSM authors) carrying these patches, just allow Yama to be called unconditionally when selected by the new CONFIG. Signed-off-by: Kees Cook Acked-by: Serge E. Hallyn Acked-by: Eric Paris Acked-by: John Johansen Signed-off-by: James Morris --- include/linux/security.h | 31 +++++++++++++++++++++++++++++++ security/security.c | 21 +++++++++++++++++++++ security/yama/Kconfig | 8 ++++++++ security/yama/yama_lsm.c | 14 ++++++++++---- 4 files changed, 70 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/security.h b/include/linux/security.h index 3dea6a9d568f..01ef030b9409 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -3021,5 +3021,36 @@ static inline void free_secdata(void *secdata) { } #endif /* CONFIG_SECURITY */ +#ifdef CONFIG_SECURITY_YAMA +extern int yama_ptrace_access_check(struct task_struct *child, + unsigned int mode); +extern int yama_ptrace_traceme(struct task_struct *parent); +extern void yama_task_free(struct task_struct *task); +extern int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, + unsigned long arg4, unsigned long arg5); +#else +static inline int yama_ptrace_access_check(struct task_struct *child, + unsigned int mode) +{ + return 0; +} + +static inline int yama_ptrace_traceme(struct task_struct *parent) +{ + return 0; +} + +static inline void yama_task_free(struct task_struct *task) +{ +} + +static inline int yama_task_prctl(int option, unsigned long arg2, + unsigned long arg3, unsigned long arg4, + unsigned long arg5) +{ + return -ENOSYS; +} +#endif /* CONFIG_SECURITY_YAMA */ + #endif /* ! __LINUX_SECURITY_H */ diff --git a/security/security.c b/security/security.c index 860aeb349cb3..68c1b9b45d93 100644 --- a/security/security.c +++ b/security/security.c @@ -136,11 +136,23 @@ int __init register_security(struct security_operations *ops) int security_ptrace_access_check(struct task_struct *child, unsigned int mode) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_ptrace_access_check(child, mode); + if (rc) + return rc; +#endif return security_ops->ptrace_access_check(child, mode); } int security_ptrace_traceme(struct task_struct *parent) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_ptrace_traceme(parent); + if (rc) + return rc; +#endif return security_ops->ptrace_traceme(parent); } @@ -761,6 +773,9 @@ int security_task_create(unsigned long clone_flags) void security_task_free(struct task_struct *task) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + yama_task_free(task); +#endif security_ops->task_free(task); } @@ -876,6 +891,12 @@ int security_task_wait(struct task_struct *p) int security_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { +#ifdef CONFIG_SECURITY_YAMA_STACKED + int rc; + rc = yama_task_prctl(option, arg2, arg3, arg4, arg5); + if (rc != -ENOSYS) + return rc; +#endif return security_ops->task_prctl(option, arg2, arg3, arg4, arg5); } diff --git a/security/yama/Kconfig b/security/yama/Kconfig index 51d6709d8bbd..20ef5143c0c0 100644 --- a/security/yama/Kconfig +++ b/security/yama/Kconfig @@ -11,3 +11,11 @@ config SECURITY_YAMA Further information can be found in Documentation/security/Yama.txt. If you are unsure how to answer this question, answer N. + +config SECURITY_YAMA_STACKED + bool "Yama stacked with other LSMs" + depends on SECURITY_YAMA + default n + help + When Yama is built into the kernel, force it to stack with the + selected primary LSM. diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c index d51b7c76c37d..9ca43c1ea630 100644 --- a/security/yama/yama_lsm.c +++ b/security/yama/yama_lsm.c @@ -100,7 +100,7 @@ static void yama_ptracer_del(struct task_struct *tracer, * yama_task_free - check for task_pid to remove from exception list * @task: task being removed */ -static void yama_task_free(struct task_struct *task) +void yama_task_free(struct task_struct *task) { yama_ptracer_del(task, task); } @@ -116,7 +116,7 @@ static void yama_task_free(struct task_struct *task) * Return 0 on success, -ve on error. -ENOSYS is returned when Yama * does not handle the given option. */ -static int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, +int yama_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { int rc; @@ -243,7 +243,7 @@ static int ptracer_exception_found(struct task_struct *tracer, * * Returns 0 if following the ptrace is allowed, -ve on error. */ -static int yama_ptrace_access_check(struct task_struct *child, +int yama_ptrace_access_check(struct task_struct *child, unsigned int mode) { int rc; @@ -296,7 +296,7 @@ static int yama_ptrace_access_check(struct task_struct *child, * * Returns 0 if following the ptrace is allowed, -ve on error. */ -static int yama_ptrace_traceme(struct task_struct *parent) +int yama_ptrace_traceme(struct task_struct *parent) { int rc; @@ -330,6 +330,7 @@ static int yama_ptrace_traceme(struct task_struct *parent) return rc; } +#ifndef CONFIG_SECURITY_YAMA_STACKED static struct security_operations yama_ops = { .name = "yama", @@ -338,6 +339,7 @@ static struct security_operations yama_ops = { .task_prctl = yama_task_prctl, .task_free = yama_task_free, }; +#endif #ifdef CONFIG_SYSCTL static int yama_dointvec_minmax(struct ctl_table *table, int write, @@ -384,13 +386,17 @@ static struct ctl_table yama_sysctl_table[] = { static __init int yama_init(void) { +#ifndef CONFIG_SECURITY_YAMA_STACKED if (!security_module_enable(&yama_ops)) return 0; +#endif printk(KERN_INFO "Yama: becoming mindful.\n"); +#ifndef CONFIG_SECURITY_YAMA_STACKED if (register_security(&yama_ops)) panic("Yama: kernel registration failed.\n"); +#endif #ifdef CONFIG_SYSCTL if (!register_sysctl_paths(yama_sysctl_path, yama_sysctl_table)) -- cgit v1.3 From 2fe5d6def1672ae6635dd71867bf36dcfaa7434b Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Mon, 13 Feb 2012 10:15:05 -0500 Subject: ima: integrity appraisal extension IMA currently maintains an integrity measurement list used to assert the integrity of the running system to a third party. The IMA-appraisal extension adds local integrity validation and enforcement of the measurement against a "good" value stored as an extended attribute 'security.ima'. The initial methods for validating 'security.ima' are hashed based, which provides file data integrity, and digital signature based, which in addition to providing file data integrity, provides authenticity. This patch creates and maintains the 'security.ima' xattr, containing the file data hash measurement. Protection of the xattr is provided by EVM, if enabled and configured. Based on policy, IMA calls evm_verifyxattr() to verify a file's metadata integrity and, assuming success, compares the file's current hash value with the one stored as an extended attribute in 'security.ima'. Changelov v4: - changed iint cache flags to hex values Changelog v3: - change appraisal default for filesystems without xattr support to fail Changelog v2: - fix audit msg 'res' value - removed unused 'ima_appraise=' values Changelog v1: - removed unused iint mutex (Dmitry Kasatkin) - setattr hook must not reset appraised (Dmitry Kasatkin) - evm_verifyxattr() now differentiates between no 'security.evm' xattr (INTEGRITY_NOLABEL) and no EVM 'protected' xattrs included in the 'security.evm' (INTEGRITY_NOXATTRS). - replace hash_status with ima_status (Dmitry Kasatkin) - re-initialize slab element ima_status on free (Dmitry Kasatkin) - include 'security.ima' in EVM if CONFIG_IMA_APPRAISE, not CONFIG_IMA - merged half "ima: ima_must_appraise_or_measure API change" (Dmitry Kasatkin) - removed unnecessary error variable in process_measurement() (Dmitry Kasatkin) - use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured (moved ima_inode_post_setattr() to ima_appraise.c) - make sure ima_collect_measurement() can read file Changelog: - add 'iint' to evm_verifyxattr() call (Dimitry Kasatkin) - fix the race condition between chmod, which takes the i_mutex and then iint->mutex, and ima_file_free() and process_measurement(), which take the locks in the reverse order, by eliminating iint->mutex. (Dmitry Kasatkin) - cleanup of ima_appraise_measurement() (Dmitry Kasatkin) - changes as a result of the iint not allocated for all regular files, but only for those measured/appraised. - don't try to appraise new/empty files - expanded ima_appraisal description in ima/Kconfig - IMA appraise definitions required even if IMA_APPRAISE not enabled - add return value to ima_must_appraise() stub - unconditionally set status = INTEGRITY_PASS *after* testing status, not before. (Found by Joe Perches) Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- Documentation/kernel-parameters.txt | 4 + include/linux/xattr.h | 3 + security/integrity/evm/evm_main.c | 3 + security/integrity/iint.c | 3 +- security/integrity/ima/Kconfig | 15 +++ security/integrity/ima/Makefile | 1 + security/integrity/ima/ima.h | 37 +++++++- security/integrity/ima/ima_api.c | 50 +++++++--- security/integrity/ima/ima_appraise.c | 168 ++++++++++++++++++++++++++++++++++ security/integrity/ima/ima_crypto.c | 8 +- security/integrity/ima/ima_main.c | 79 +++++++++++----- security/integrity/ima/ima_policy.c | 32 +++++-- security/integrity/integrity.h | 8 +- 13 files changed, 358 insertions(+), 53 deletions(-) create mode 100644 security/integrity/ima/ima_appraise.c (limited to 'include/linux') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index ad7e2e5088c1..fa09e64d9877 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1051,6 +1051,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ihash_entries= [KNL] Set number of hash buckets for inode cache. + ima_appraise= [IMA] appraise integrity measurements + Format: { "off" | "enforce" | "fix" } + default: "enforce" + ima_audit= [IMA] Format: { "0" | "1" } 0 -- integrity auditing messages. (Default) diff --git a/include/linux/xattr.h b/include/linux/xattr.h index e5d122031542..77a3e686d566 100644 --- a/include/linux/xattr.h +++ b/include/linux/xattr.h @@ -33,6 +33,9 @@ #define XATTR_EVM_SUFFIX "evm" #define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX +#define XATTR_IMA_SUFFIX "ima" +#define XATTR_NAME_IMA XATTR_SECURITY_PREFIX XATTR_IMA_SUFFIX + #define XATTR_SELINUX_SUFFIX "selinux" #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 8901501425f4..eb5484504f50 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -33,6 +33,9 @@ char *evm_config_xattrnames[] = { #endif #ifdef CONFIG_SECURITY_SMACK XATTR_NAME_SMACK, +#endif +#ifdef CONFIG_IMA_APPRAISE + XATTR_NAME_IMA, #endif XATTR_NAME_CAPS, NULL diff --git a/security/integrity/iint.c b/security/integrity/iint.c index 399641c3e846..e600986aa49f 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -74,6 +74,7 @@ static void iint_free(struct integrity_iint_cache *iint) { iint->version = 0; iint->flags = 0UL; + iint->ima_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; kmem_cache_free(iint_cache, iint); } @@ -157,7 +158,7 @@ static void init_once(void *foo) memset(iint, 0, sizeof *iint); iint->version = 0; iint->flags = 0UL; - mutex_init(&iint->mutex); + iint->ima_status = INTEGRITY_UNKNOWN; iint->evm_status = INTEGRITY_UNKNOWN; } diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 809ccf19d09c..d232c73647ae 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -56,3 +56,18 @@ config IMA_LSM_RULES default y help Disabling this option will disregard LSM based policy rules. + +config IMA_APPRAISE + bool "Appraise integrity measurements" + depends on IMA + default n + help + This option enables local measurement integrity appraisal. + It requires the system to be labeled with a security extended + attribute containing the file hash measurement. To protect + the security extended attributes from offline attack, enable + and configure EVM. + + For more information on integrity appraisal refer to: + + If unsure, say N. diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 5f740f6971e1..3f2ca6bdc384 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_IMA) += ima.o ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ ima_policy.o ima-$(CONFIG_IMA_AUDIT) += ima_audit.o +ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e7c99fd0d223..069a4aa63e95 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -40,6 +40,7 @@ enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; extern int ima_initialized; extern int ima_used_chip; extern char *ima_hash; +extern int ima_appraise; /* IMA inode template definition */ struct ima_template_data { @@ -107,6 +108,7 @@ static inline unsigned long ima_hash_key(u8 *digest) } /* LIM API function definitions */ +int ima_must_appraise_or_measure(struct inode *inode, int mask, int function); int ima_must_measure(struct inode *inode, int mask, int function); int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file); @@ -123,14 +125,45 @@ struct integrity_iint_cache *integrity_iint_insert(struct inode *inode); struct integrity_iint_cache *integrity_iint_find(struct inode *inode); /* IMA policy related functions */ -enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK }; +enum ima_hooks { FILE_CHECK = 1, FILE_MMAP, BPRM_CHECK, POST_SETATTR }; -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask); +int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, + int flags); void ima_init_policy(void); void ima_update_policy(void); ssize_t ima_parse_add_rule(char *); void ima_delete_rules(void); +/* Appraise integrity measurements */ +#define IMA_APPRAISE_ENFORCE 0x01 +#define IMA_APPRAISE_FIX 0x02 + +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename); +int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask); +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file); + +#else +static inline int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, + const unsigned char *filename) +{ + return INTEGRITY_UNKNOWN; +} + +static inline int ima_must_appraise(struct inode *inode, + enum ima_hooks func, int mask) +{ + return 0; +} + +static inline void ima_update_xattr(struct integrity_iint_cache *iint, + struct file *file) +{ +} +#endif + /* LSM based policy rules require audit */ #ifdef CONFIG_IMA_LSM_RULES diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c index 032ff03ad907..41cce84416c5 100644 --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -9,13 +9,17 @@ * License. * * File: ima_api.c - * Implements must_measure, collect_measurement, store_measurement, - * and store_template. + * Implements must_appraise_or_measure, collect_measurement, + * appraise_measurement, store_measurement and store_template. */ #include #include - +#include +#include +#include +#include #include "ima.h" + static const char *IMA_TEMPLATE_NAME = "ima"; /* @@ -93,7 +97,7 @@ err_out: } /** - * ima_must_measure - measure decision based on policy. + * ima_must_appraise_or_measure - appraise & measure decision based on policy. * @inode: pointer to inode to measure * @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE) * @function: calling function (FILE_CHECK, BPRM_CHECK, FILE_MMAP) @@ -105,15 +109,22 @@ err_out: * mask: contains the permission mask * fsmagic: hex value * - * Return 0 to measure. For matching a DONT_MEASURE policy, no policy, - * or other error, return an error code. -*/ -int ima_must_measure(struct inode *inode, int mask, int function) + * Returns IMA_MEASURE, IMA_APPRAISE mask. + * + */ +int ima_must_appraise_or_measure(struct inode *inode, int mask, int function) { - int must_measure; + int flags = IMA_MEASURE | IMA_APPRAISE; + + if (!ima_appraise) + flags &= ~IMA_APPRAISE; + + return ima_match_policy(inode, function, mask, flags); +} - must_measure = ima_match_policy(inode, function, mask); - return must_measure ? 0 : -EACCES; +int ima_must_measure(struct inode *inode, int mask, int function) +{ + return ima_match_policy(inode, function, mask, IMA_MEASURE); } /* @@ -129,16 +140,24 @@ int ima_must_measure(struct inode *inode, int mask, int function) int ima_collect_measurement(struct integrity_iint_cache *iint, struct file *file) { - int result = -EEXIST; + struct inode *inode = file->f_dentry->d_inode; + const char *filename = file->f_dentry->d_name.name; + int result = 0; - if (!(iint->flags & IMA_MEASURED)) { + if (!(iint->flags & IMA_COLLECTED)) { u64 i_version = file->f_dentry->d_inode->i_version; memset(iint->digest, 0, IMA_DIGEST_SIZE); result = ima_calc_hash(file, iint->digest); - if (!result) + if (!result) { iint->version = i_version; + iint->flags |= IMA_COLLECTED; + } } + if (result) + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, + filename, "collect_data", "failed", + result, 0); return result; } @@ -167,6 +186,9 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct ima_template_entry *entry; int violation = 0; + if (iint->flags & IMA_MEASURED) + return; + entry = kmalloc(sizeof(*entry), GFP_KERNEL); if (!entry) { integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c new file mode 100644 index 000000000000..4865f61f9044 --- /dev/null +++ b/security/integrity/ima/ima_appraise.c @@ -0,0 +1,168 @@ +/* + * Copyright (C) 2011 IBM Corporation + * + * Author: + * Mimi Zohar + * + * 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 +#include +#include +#include +#include +#include +#include + +#include "ima.h" + +static int __init default_appraise_setup(char *str) +{ + if (strncmp(str, "off", 3) == 0) + ima_appraise = 0; + else if (strncmp(str, "fix", 3) == 0) + ima_appraise = IMA_APPRAISE_FIX; + return 1; +} + +__setup("ima_appraise=", default_appraise_setup); + +/* + * ima_must_appraise - set appraise flag + * + * Return 1 to appraise + */ +int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask) +{ + return 0; +} + +static void ima_fix_xattr(struct dentry *dentry, + struct integrity_iint_cache *iint) +{ + iint->digest[0] = IMA_XATTR_DIGEST; + __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, + iint->digest, IMA_DIGEST_SIZE + 1, 0); +} + +/* + * ima_appraise_measurement - appraise file measurement + * + * Call evm_verifyxattr() to verify the integrity of 'security.ima'. + * Assuming success, compare the xattr hash with the collected measurement. + * + * Return 0 on success, error code otherwise + */ +int ima_appraise_measurement(struct integrity_iint_cache *iint, + struct file *file, const unsigned char *filename) +{ + struct dentry *dentry = file->f_dentry; + struct inode *inode = dentry->d_inode; + u8 xattr_value[IMA_DIGEST_SIZE]; + enum integrity_status status = INTEGRITY_UNKNOWN; + const char *op = "appraise_data"; + char *cause = "unknown"; + int rc; + + if (!ima_appraise) + return 0; + if (!inode->i_op->getxattr) + return INTEGRITY_UNKNOWN; + + if (iint->flags & IMA_APPRAISED) + return iint->ima_status; + + rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, xattr_value, + IMA_DIGEST_SIZE); + if (rc <= 0) { + if (rc && rc != -ENODATA) + goto out; + + cause = "missing-hash"; + status = + (inode->i_size == 0) ? INTEGRITY_PASS : INTEGRITY_NOLABEL; + goto out; + } + + status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint); + if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) { + if ((status == INTEGRITY_NOLABEL) + || (status == INTEGRITY_NOXATTRS)) + cause = "missing-HMAC"; + else if (status == INTEGRITY_FAIL) + cause = "invalid-HMAC"; + goto out; + } + + rc = memcmp(xattr_value, iint->digest, IMA_DIGEST_SIZE); + if (rc) { + status = INTEGRITY_FAIL; + cause = "invalid-hash"; + print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE, + xattr_value, IMA_DIGEST_SIZE); + print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE, + iint->digest, IMA_DIGEST_SIZE); + goto out; + } + status = INTEGRITY_PASS; + iint->flags |= IMA_APPRAISED; +out: + if (status != INTEGRITY_PASS) { + if (ima_appraise & IMA_APPRAISE_FIX) { + ima_fix_xattr(dentry, iint); + status = INTEGRITY_PASS; + } + integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode, filename, + op, cause, rc, 0); + } + iint->ima_status = status; + return status; +} + +/* + * ima_update_xattr - update 'security.ima' hash value + */ +void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) +{ + struct dentry *dentry = file->f_dentry; + int rc = 0; + + rc = ima_collect_measurement(iint, file); + if (rc < 0) + return; + ima_fix_xattr(dentry, iint); +} + +/** + * ima_inode_post_setattr - reflect file metadata changes + * @dentry: pointer to the affected dentry + * + * Changes to a dentry's metadata might result in needing to appraise. + * + * This function is called from notify_change(), which expects the caller + * to lock the inode's i_mutex. + */ +void ima_inode_post_setattr(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + struct integrity_iint_cache *iint; + int must_appraise, rc; + + if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode) + || !inode->i_op->removexattr) + return; + + must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR); + iint = integrity_iint_find(inode); + if (iint) { + if (must_appraise) + iint->flags |= IMA_APPRAISE; + else + iint->flags &= ~(IMA_APPRAISE | IMA_APPRAISED); + } + if (!must_appraise) + rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); + return; +} diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 9b3ade7468b2..b21ee5b5495a 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -48,7 +48,7 @@ int ima_calc_hash(struct file *file, char *digest) struct scatterlist sg[1]; loff_t i_size, offset = 0; char *rbuf; - int rc; + int rc, read = 0; rc = init_desc(&desc); if (rc != 0) @@ -59,6 +59,10 @@ int ima_calc_hash(struct file *file, char *digest) rc = -ENOMEM; goto out; } + if (!(file->f_mode & FMODE_READ)) { + file->f_mode |= FMODE_READ; + read = 1; + } i_size = i_size_read(file->f_dentry->d_inode); while (offset < i_size) { int rbuf_len; @@ -80,6 +84,8 @@ int ima_calc_hash(struct file *file, char *digest) kfree(rbuf); if (!rc) rc = crypto_hash_final(&desc, digest); + if (read) + file->f_mode &= ~FMODE_READ; out: crypto_free_hash(desc.tfm); return rc; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index be8294915cf7..6eb28d47e74b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -22,12 +22,19 @@ #include #include #include +#include #include #include "ima.h" int ima_initialized; +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise = IMA_APPRAISE_ENFORCE; +#else +int ima_appraise; +#endif + char *ima_hash = "sha1"; static int __init hash_setup(char *str) { @@ -52,7 +59,7 @@ static void ima_rdwr_violation_check(struct file *file) struct dentry *dentry = file->f_path.dentry; struct inode *inode = dentry->d_inode; fmode_t mode = file->f_mode; - int rc; + int must_measure; bool send_tomtou = false, send_writers = false; unsigned char *pathname = NULL, *pathbuf = NULL; @@ -67,8 +74,8 @@ static void ima_rdwr_violation_check(struct file *file) goto out; } - rc = ima_must_measure(inode, MAY_READ, FILE_CHECK); - if (rc < 0) + must_measure = ima_must_measure(inode, MAY_READ, FILE_CHECK); + if (!must_measure) goto out; if (atomic_read(&inode->i_writecount) > 0) @@ -100,17 +107,21 @@ out: } static void ima_check_last_writer(struct integrity_iint_cache *iint, - struct inode *inode, - struct file *file) + struct inode *inode, struct file *file) { fmode_t mode = file->f_mode; - mutex_lock(&iint->mutex); - if (mode & FMODE_WRITE && - atomic_read(&inode->i_writecount) == 1 && - iint->version != inode->i_version) - iint->flags &= ~IMA_MEASURED; - mutex_unlock(&iint->mutex); + if (!(mode & FMODE_WRITE)) + return; + + mutex_lock(&inode->i_mutex); + if (atomic_read(&inode->i_writecount) == 1 && + iint->version != inode->i_version) { + iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + if (iint->flags & IMA_APPRAISE) + ima_update_xattr(iint, file); + } + mutex_unlock(&inode->i_mutex); } /** @@ -140,14 +151,17 @@ static int process_measurement(struct file *file, const unsigned char *filename, struct inode *inode = file->f_dentry->d_inode; struct integrity_iint_cache *iint; unsigned char *pathname = NULL, *pathbuf = NULL; - int rc = 0; + int rc = -ENOMEM, action, must_appraise; if (!ima_initialized || !S_ISREG(inode->i_mode)) return 0; - rc = ima_must_measure(inode, mask, function); - if (rc != 0) - return rc; + /* Determine if in appraise/measurement policy, + * returns IMA_MEASURE, IMA_APPRAISE bitmask. */ + action = ima_must_appraise_or_measure(inode, mask, function); + if (!action) + return 0; + retry: iint = integrity_iint_find(inode); if (!iint) { @@ -157,11 +171,21 @@ retry: return rc; } - mutex_lock(&iint->mutex); + must_appraise = action & IMA_APPRAISE; - rc = iint->flags & IMA_MEASURED ? 1 : 0; - if (rc != 0) + mutex_lock(&inode->i_mutex); + + /* Determine if already appraised/measured based on bitmask + * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ + iint->flags |= action; + action &= ~((iint->flags & (IMA_MEASURED | IMA_APPRAISED)) >> 1); + + /* Nothing to do, just return existing appraised status */ + if (!action) { + if (iint->flags & IMA_APPRAISED) + rc = iint->ima_status; goto out; + } rc = ima_collect_measurement(iint, file); if (rc != 0) @@ -177,11 +201,16 @@ retry: pathname = NULL; } } - ima_store_measurement(iint, file, !pathname ? filename : pathname); + if (action & IMA_MEASURE) + ima_store_measurement(iint, file, + !pathname ? filename : pathname); + if (action & IMA_APPRAISE) + rc = ima_appraise_measurement(iint, file, + !pathname ? filename : pathname); kfree(pathbuf); out: - mutex_unlock(&iint->mutex); - return rc; + mutex_unlock(&inode->i_mutex); + return (rc && must_appraise) ? -EACCES : 0; } /** @@ -197,14 +226,14 @@ out: */ int ima_file_mmap(struct file *file, unsigned long prot) { - int rc; + int rc = 0; if (!file) return 0; if (prot & PROT_EXEC) rc = process_measurement(file, file->f_dentry->d_name.name, MAY_EXEC, FILE_MMAP); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } /** @@ -228,7 +257,7 @@ int ima_bprm_check(struct linux_binprm *bprm) (strcmp(bprm->filename, bprm->interp) == 0) ? bprm->filename : bprm->interp, MAY_EXEC, BPRM_CHECK); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } /** @@ -249,7 +278,7 @@ int ima_file_check(struct file *file, int mask) rc = process_measurement(file, file->f_dentry->d_name.name, mask & (MAY_READ | MAY_WRITE | MAY_EXEC), FILE_CHECK); - return 0; + return (ima_appraise & IMA_APPRAISE_ENFORCE) ? rc : 0; } EXPORT_SYMBOL_GPL(ima_file_check); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 1a9583008aae..3e22e17da295 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -25,7 +25,13 @@ #define IMA_FSMAGIC 0x0004 #define IMA_UID 0x0008 -enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE }; +#define UNKNOWN 0 +#define MEASURE 1 /* same as IMA_MEASURE */ +#define DONT_MEASURE 2 +#define MEASURE_MASK 3 +#define APPRAISE 4 /* same as IMA_APPRAISE */ +#define DONT_APPRAISE 8 +#define APPRAISE_MASK 12 #define MAX_LSM_RULES 6 enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, @@ -34,7 +40,7 @@ enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE, struct ima_measure_rule_entry { struct list_head list; - enum ima_action action; + int action; unsigned int flags; enum ima_hooks func; int mask; @@ -163,18 +169,28 @@ static bool ima_match_rules(struct ima_measure_rule_entry *rule, * as elements in the list are never deleted, nor does the list * change.) */ -int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask) +int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, + int flags) { struct ima_measure_rule_entry *entry; + int action = 0, actmask = flags | (flags << 1); list_for_each_entry(entry, ima_measure, list) { - bool rc; - rc = ima_match_rules(entry, inode, func, mask); - if (rc) - return entry->action; + if (!(entry->action & actmask)) + continue; + + if (!ima_match_rules(entry, inode, func, mask)) + continue; + + action |= (entry->action & (IMA_APPRAISE | IMA_MEASURE)); + actmask &= (entry->action & APPRAISE_MASK) ? + ~APPRAISE_MASK : ~MEASURE_MASK; + if (!actmask) + break; } - return 0; + + return action; } /** diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 7a25ecec5aaa..dac6b68e945a 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -16,7 +16,11 @@ #include /* iint cache flags */ -#define IMA_MEASURED 0x01 +#define IMA_MEASURE 0x01 +#define IMA_MEASURED 0x02 +#define IMA_APPRAISE 0x04 +#define IMA_APPRAISED 0x08 +#define IMA_COLLECTED 0x10 enum evm_ima_xattr_type { IMA_XATTR_DIGEST = 0x01, @@ -36,7 +40,7 @@ struct integrity_iint_cache { u64 version; /* track inode changes */ unsigned char flags; u8 digest[SHA1_DIGEST_SIZE]; - struct mutex mutex; /* protects: version, flags, digest */ + enum integrity_status ima_status; enum integrity_status evm_status; }; -- cgit v1.3 From bf2276d10ce58ff44ab8857266a6718024496af6 Mon Sep 17 00:00:00 2001 From: Dmitry Kasatkin Date: Wed, 19 Oct 2011 12:04:40 +0300 Subject: ima: allocating iint improvements With IMA-appraisal's removal of the iint mutex and taking the i_mutex instead, allocating the iint becomes a lot simplier, as we don't need to be concerned with two processes racing to allocate the iint. This patch cleans up and improves performance for allocating the iint. - removed redundant double i_mutex locking - combined iint allocation with tree search Changelog v2: - removed the rwlock/read_lock changes from this patch Signed-off-by: Dmitry Kasatkin Signed-off-by: Mimi Zohar --- include/linux/integrity.h | 7 +++--- security/integrity/iint.c | 45 +++++++++++++++++---------------------- security/integrity/ima/ima_main.c | 13 ++++------- 3 files changed, 27 insertions(+), 38 deletions(-) (limited to 'include/linux') diff --git a/include/linux/integrity.h b/include/linux/integrity.h index a0c41256cb92..66c5fe9550a5 100644 --- a/include/linux/integrity.h +++ b/include/linux/integrity.h @@ -22,13 +22,14 @@ enum integrity_status { /* List of EVM protected security xattrs */ #ifdef CONFIG_INTEGRITY -extern int integrity_inode_alloc(struct inode *inode); +extern struct integrity_iint_cache *integrity_inode_get(struct inode *inode); extern void integrity_inode_free(struct inode *inode); #else -static inline int integrity_inode_alloc(struct inode *inode) +static inline struct integrity_iint_cache * + integrity_inode_get(struct inode *inode) { - return 0; + return NULL; } static inline void integrity_inode_free(struct inode *inode) diff --git a/security/integrity/iint.c b/security/integrity/iint.c index e600986aa49f..c91a436e13ac 100644 --- a/security/integrity/iint.c +++ b/security/integrity/iint.c @@ -80,24 +80,26 @@ static void iint_free(struct integrity_iint_cache *iint) } /** - * integrity_inode_alloc - allocate an iint associated with an inode + * integrity_inode_get - find or allocate an iint associated with an inode * @inode: pointer to the inode + * @return: allocated iint + * + * Caller must lock i_mutex */ -int integrity_inode_alloc(struct inode *inode) +struct integrity_iint_cache *integrity_inode_get(struct inode *inode) { struct rb_node **p; - struct rb_node *new_node, *parent = NULL; - struct integrity_iint_cache *new_iint, *test_iint; - int rc; + struct rb_node *node, *parent = NULL; + struct integrity_iint_cache *iint, *test_iint; - new_iint = kmem_cache_alloc(iint_cache, GFP_NOFS); - if (!new_iint) - return -ENOMEM; + iint = integrity_iint_find(inode); + if (iint) + return iint; - new_iint->inode = inode; - new_node = &new_iint->rb_node; + iint = kmem_cache_alloc(iint_cache, GFP_NOFS); + if (!iint) + return NULL; - mutex_lock(&inode->i_mutex); /* i_flags */ spin_lock(&integrity_iint_lock); p = &integrity_iint_tree.rb_node; @@ -105,29 +107,20 @@ int integrity_inode_alloc(struct inode *inode) parent = *p; test_iint = rb_entry(parent, struct integrity_iint_cache, rb_node); - rc = -EEXIST; if (inode < test_iint->inode) p = &(*p)->rb_left; - else if (inode > test_iint->inode) - p = &(*p)->rb_right; else - goto out_err; + p = &(*p)->rb_right; } + iint->inode = inode; + node = &iint->rb_node; inode->i_flags |= S_IMA; - rb_link_node(new_node, parent, p); - rb_insert_color(new_node, &integrity_iint_tree); + rb_link_node(node, parent, p); + rb_insert_color(node, &integrity_iint_tree); spin_unlock(&integrity_iint_lock); - mutex_unlock(&inode->i_mutex); /* i_flags */ - - return 0; -out_err: - spin_unlock(&integrity_iint_lock); - mutex_unlock(&inode->i_mutex); /* i_flags */ - iint_free(new_iint); - - return rc; + return iint; } /** diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 6eb28d47e74b..df6521296051 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -162,19 +162,14 @@ static int process_measurement(struct file *file, const unsigned char *filename, if (!action) return 0; -retry: - iint = integrity_iint_find(inode); - if (!iint) { - rc = integrity_inode_alloc(inode); - if (!rc || rc == -EEXIST) - goto retry; - return rc; - } - must_appraise = action & IMA_APPRAISE; mutex_lock(&inode->i_mutex); + iint = integrity_inode_get(inode); + if (!iint) + goto out; + /* Determine if already appraised/measured based on bitmask * (IMA_MEASURE, IMA_MEASURED, IMA_APPRAISE, IMA_APPRAISED) */ iint->flags |= action; -- cgit v1.3 From 9957a5043e7b0b7361cdf48eea22b2900293e63a Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Wed, 9 Mar 2011 22:57:53 -0500 Subject: ima: add inode_post_setattr call Changing an inode's metadata may result in our not needing to appraise the file. In such cases, we must remove 'security.ima'. Changelog v1: - use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured Signed-off-by: Mimi Zohar Acked-by: Serge Hallyn Acked-by: Dmitry Kasatkin --- fs/attr.c | 2 ++ include/linux/ima.h | 10 ++++++++++ 2 files changed, 12 insertions(+) (limited to 'include/linux') diff --git a/fs/attr.c b/fs/attr.c index 29e38a1f7f77..cce7df53b694 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -14,6 +14,7 @@ #include #include #include +#include /** * inode_change_ok - check if attribute changes to an inode are allowed @@ -247,6 +248,7 @@ int notify_change(struct dentry * dentry, struct iattr * attr) if (!error) { fsnotify_change(dentry, ia_valid); + ima_inode_post_setattr(dentry); evm_inode_post_setattr(dentry, ia_valid); } diff --git a/include/linux/ima.h b/include/linux/ima.h index 6ac8e50c6cf5..e2bfbb1e9af6 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -39,5 +39,15 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot) { return 0; } + #endif /* CONFIG_IMA_H */ + +#ifdef CONFIG_IMA_APPRAISE +extern void ima_inode_post_setattr(struct dentry *dentry); +#else +static inline void ima_inode_post_setattr(struct dentry *dentry) +{ + return; +} +#endif /* CONFIG_IMA_APPRAISE_H */ #endif /* _LINUX_IMA_H */ -- cgit v1.3 From 42c63330f2b05aa6077c1bfc2798c04afe54f6b2 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Thu, 10 Mar 2011 18:54:15 -0500 Subject: ima: add ima_inode_setxattr/removexattr function and calls Based on xattr_permission comments, the restriction to modify 'security' xattr is left up to the underlying fs or lsm. Ensure that not just anyone can modify or remove 'security.ima'. Changelog v1: - Unless IMA-APPRAISE is configured, use stub ima_inode_removexattr()/setxattr() functions. (Moved ima_inode_removexattr()/setxattr() to ima_appraise.c) Changelog: - take i_mutex to fix locking (Dmitry Kasatkin) - ima_reset_appraise_flags should only be called when modifying or removing the 'security.ima' xattr. Requires CAP_SYS_ADMIN privilege. (Incorporated fix from Roberto Sassu) - Even if allowed to update security.ima, reset the appraisal flags, forcing re-appraisal. - Replace CAP_MAC_ADMIN with CAP_SYS_ADMIN - static inline ima_inode_setxattr()/ima_inode_removexattr() stubs - ima_protect_xattr should be static Signed-off-by: Mimi Zohar Signed-off-by: Dmitry Kasatkin --- include/linux/ima.h | 17 +++++++++++ security/integrity/ima/ima_appraise.c | 57 +++++++++++++++++++++++++++++++++++ security/security.c | 6 ++++ 3 files changed, 80 insertions(+) (limited to 'include/linux') diff --git a/include/linux/ima.h b/include/linux/ima.h index e2bfbb1e9af6..2c7223d7e73b 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -44,10 +44,27 @@ static inline int ima_file_mmap(struct file *file, unsigned long prot) #ifdef CONFIG_IMA_APPRAISE extern void ima_inode_post_setattr(struct dentry *dentry); +extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len); +extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name); #else static inline void ima_inode_post_setattr(struct dentry *dentry) { return; } + +static inline int ima_inode_setxattr(struct dentry *dentry, + const char *xattr_name, + const void *xattr_value, + size_t xattr_value_len) +{ + return 0; +} + +static inline int ima_inode_removexattr(struct dentry *dentry, + const char *xattr_name) +{ + return 0; +} #endif /* CONFIG_IMA_APPRAISE_H */ #endif /* _LINUX_IMA_H */ diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 681cb6e72257..becc7e09116d 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -169,3 +169,60 @@ void ima_inode_post_setattr(struct dentry *dentry) rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); return; } + +/* + * ima_protect_xattr - protect 'security.ima' + * + * Ensure that not just anyone can modify or remove 'security.ima'. + */ +static int ima_protect_xattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + if (strcmp(xattr_name, XATTR_NAME_IMA) == 0) { + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return 1; + } + return 0; +} + +static void ima_reset_appraise_flags(struct inode *inode) +{ + struct integrity_iint_cache *iint; + + if (!ima_initialized || !ima_appraise || !S_ISREG(inode->i_mode)) + return; + + iint = integrity_iint_find(inode); + if (!iint) + return; + + iint->flags &= ~(IMA_COLLECTED | IMA_APPRAISED | IMA_MEASURED); + return; +} + +int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, xattr_value, + xattr_value_len); + if (result == 1) { + ima_reset_appraise_flags(dentry->d_inode); + result = 0; + } + return result; +} + +int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, NULL, 0); + if (result == 1) { + ima_reset_appraise_flags(dentry->d_inode); + result = 0; + } + return result; +} diff --git a/security/security.c b/security/security.c index 68c1b9b45d93..d23b43522a5a 100644 --- a/security/security.c +++ b/security/security.c @@ -571,6 +571,9 @@ int security_inode_setxattr(struct dentry *dentry, const char *name, if (unlikely(IS_PRIVATE(dentry->d_inode))) return 0; ret = security_ops->inode_setxattr(dentry, name, value, size, flags); + if (ret) + return ret; + ret = ima_inode_setxattr(dentry, name, value, size); if (ret) return ret; return evm_inode_setxattr(dentry, name, value, size); @@ -606,6 +609,9 @@ int security_inode_removexattr(struct dentry *dentry, const char *name) if (unlikely(IS_PRIVATE(dentry->d_inode))) return 0; ret = security_ops->inode_removexattr(dentry, name); + if (ret) + return ret; + ret = ima_inode_removexattr(dentry, name); if (ret) return ret; return evm_inode_removexattr(dentry, name); -- cgit v1.3 From e23eb920b0f3978687c497de2ac3eb9e281dab32 Mon Sep 17 00:00:00 2001 From: Peter Moody Date: Thu, 14 Jun 2012 10:04:35 -0700 Subject: audit: export audit_log_task_info At the suggestion of eparis@redhat.com, move this chunk of task logging from audit_log_exit to audit_log_task_info and export this function so it's usuable elsewhere in the kernel. This patch is against git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity#next-ima-appraisal Changelog v2: - add empty audit_log_task_info if CONFIG_AUDITSYSCALL isn't set. Changelog v1: - Initial post. Signed-off-by: Peter Moody Signed-off-by: Mimi Zohar --- include/linux/audit.h | 2 ++ kernel/auditsc.c | 74 +++++++++++++++++++++++---------------------------- 2 files changed, 36 insertions(+), 40 deletions(-) (limited to 'include/linux') diff --git a/include/linux/audit.h b/include/linux/audit.h index 36abf2aa7e68..2a5073cf548a 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -529,6 +529,7 @@ extern int audit_set_loginuid(uid_t loginuid); #define audit_get_loginuid(t) ((t)->loginuid) #define audit_get_sessionid(t) ((t)->sessionid) extern void audit_log_task_context(struct audit_buffer *ab); +extern void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk); extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp); extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode); extern int __audit_bprm(struct linux_binprm *bprm); @@ -640,6 +641,7 @@ extern int audit_signals; #define audit_get_loginuid(t) (-1) #define audit_get_sessionid(t) (-1) #define audit_log_task_context(b) do { ; } while (0) +#define audit_log_task_info(b, t) do { ; } while (0) #define audit_ipc_obj(i) ((void)0) #define audit_ipc_set_perm(q,u,g,m) ((void)0) #define audit_bprm(p) ({ 0; }) diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 4b96415527b8..37f52f27828d 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1154,13 +1154,38 @@ error_path: EXPORT_SYMBOL(audit_log_task_context); -static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) +void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) { + const struct cred *cred; char name[sizeof(tsk->comm)]; struct mm_struct *mm = tsk->mm; struct vm_area_struct *vma; + char *tty; + + if (!ab) + return; /* tsk == current */ + cred = current_cred(); + + spin_lock_irq(&tsk->sighand->siglock); + if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) + tty = tsk->signal->tty->name; + else + tty = "(none)"; + spin_unlock_irq(&tsk->sighand->siglock); + + + audit_log_format(ab, + " ppid=%ld pid=%d auid=%u uid=%u gid=%u" + " euid=%u suid=%u fsuid=%u" + " egid=%u sgid=%u fsgid=%u ses=%u tty=%s", + sys_getppid(), + tsk->pid, + tsk->loginuid, cred->uid, cred->gid, + cred->euid, cred->suid, cred->fsuid, + cred->egid, cred->sgid, cred->fsgid, + tsk->sessionid, tty); get_task_comm(name, tsk); audit_log_format(ab, " comm="); @@ -1183,6 +1208,8 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk audit_log_task_context(ab); } +EXPORT_SYMBOL(audit_log_task_info); + static int audit_log_pid_context(struct audit_context *context, pid_t pid, uid_t auid, uid_t uid, unsigned int sessionid, u32 sid, char *comm) @@ -1585,26 +1612,12 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n, static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { - const struct cred *cred; int i, call_panic = 0; struct audit_buffer *ab; struct audit_aux_data *aux; - const char *tty; struct audit_names *n; /* tsk == current */ - context->pid = tsk->pid; - if (!context->ppid) - context->ppid = sys_getppid(); - cred = current_cred(); - context->uid = cred->uid; - context->gid = cred->gid; - context->euid = cred->euid; - context->suid = cred->suid; - context->fsuid = cred->fsuid; - context->egid = cred->egid; - context->sgid = cred->sgid; - context->fsgid = cred->fsgid; context->personality = tsk->personality; ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL); @@ -1619,32 +1632,13 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", context->return_code); - spin_lock_irq(&tsk->sighand->siglock); - if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) - tty = tsk->signal->tty->name; - else - tty = "(none)"; - spin_unlock_irq(&tsk->sighand->siglock); - audit_log_format(ab, - " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" - " ppid=%d pid=%d auid=%u uid=%u gid=%u" - " euid=%u suid=%u fsuid=%u" - " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", - context->argv[0], - context->argv[1], - context->argv[2], - context->argv[3], - context->name_count, - context->ppid, - context->pid, - tsk->loginuid, - context->uid, - context->gid, - context->euid, context->suid, context->fsuid, - context->egid, context->sgid, context->fsgid, tty, - tsk->sessionid); - + " a0=%lx a1=%lx a2=%lx a3=%lx items=%d", + context->argv[0], + context->argv[1], + context->argv[2], + context->argv[3], + context->name_count); audit_log_task_info(ab, tsk); audit_log_key(ab, context->filterkey); -- cgit v1.3