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author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-01-24 12:37:43 -0800 |
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committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2017-01-24 12:37:43 -0800 |
commit | 0cce284537fb42d9c28b9b31038ffc9b464555f5 (patch) | |
tree | e7af3b5fe2d04ef6527b5da50851d498ee13184e /security/integrity/ima | |
parent | cefb26d4b37c329f624eb235a1bdc7b6b8dd9430 (diff) | |
parent | 7a308bb3016f57e5be11a677d15b821536419d36 (diff) | |
download | blackbird-obmc-linux-0cce284537fb42d9c28b9b31038ffc9b464555f5.tar.gz blackbird-obmc-linux-0cce284537fb42d9c28b9b31038ffc9b464555f5.zip |
Merge tag 'v4.10-rc5' into next
Sync up with mainline to bring up improvements in various subsystems.
Diffstat (limited to 'security/integrity/ima')
-rw-r--r-- | security/integrity/ima/Kconfig | 12 | ||||
-rw-r--r-- | security/integrity/ima/Makefile | 1 | ||||
-rw-r--r-- | security/integrity/ima/ima.h | 31 | ||||
-rw-r--r-- | security/integrity/ima/ima_appraise.c | 38 | ||||
-rw-r--r-- | security/integrity/ima/ima_crypto.c | 6 | ||||
-rw-r--r-- | security/integrity/ima/ima_fs.c | 32 | ||||
-rw-r--r-- | security/integrity/ima/ima_init.c | 5 | ||||
-rw-r--r-- | security/integrity/ima/ima_kexec.c | 168 | ||||
-rw-r--r-- | security/integrity/ima/ima_main.c | 3 | ||||
-rw-r--r-- | security/integrity/ima/ima_queue.c | 77 | ||||
-rw-r--r-- | security/integrity/ima/ima_template.c | 297 | ||||
-rw-r--r-- | security/integrity/ima/ima_template_lib.c | 7 |
12 files changed, 622 insertions, 55 deletions
diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 5487827fa86c..370eb2f4dd37 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -27,6 +27,18 @@ config IMA to learn more about IMA. If unsure, say N. +config IMA_KEXEC + bool "Enable carrying the IMA measurement list across a soft boot" + depends on IMA && TCG_TPM && HAVE_IMA_KEXEC + default n + help + TPM PCRs are only reset on a hard reboot. In order to validate + a TPM's quote after a soft boot, the IMA measurement list of the + running kernel must be saved and restored on boot. + + Depending on the IMA policy, the measurement list can grow to + be very large. + config IMA_MEASURE_PCR_IDX int depends on IMA diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile index 9aeaedad1e2b..29f198bde02b 100644 --- a/security/integrity/ima/Makefile +++ b/security/integrity/ima/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_IMA) += ima.o ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \ ima_policy.o ima_template.o ima_template_lib.o ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o +ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index db25f54a04fe..5e6180a4da7d 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -28,6 +28,10 @@ #include "../integrity.h" +#ifdef CONFIG_HAVE_IMA_KEXEC +#include <asm/ima.h> +#endif + enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_BINARY_NO_FIELD_LEN, IMA_SHOW_BINARY_OLD_STRING_FMT, IMA_SHOW_ASCII }; enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 }; @@ -81,6 +85,7 @@ struct ima_template_field { /* IMA template descriptor definition */ struct ima_template_desc { + struct list_head list; char *name; char *fmt; int num_fields; @@ -102,6 +107,27 @@ struct ima_queue_entry { }; extern struct list_head ima_measurements; /* list of all measurements */ +/* Some details preceding the binary serialized measurement list */ +struct ima_kexec_hdr { + u16 version; + u16 _reserved0; + u32 _reserved1; + u64 buffer_size; + u64 count; +}; + +#ifdef CONFIG_HAVE_IMA_KEXEC +void ima_load_kexec_buffer(void); +#else +static inline void ima_load_kexec_buffer(void) {} +#endif /* CONFIG_HAVE_IMA_KEXEC */ + +/* + * The default binary_runtime_measurements list format is defined as the + * platform native format. The canonical format is defined as little-endian. + */ +extern bool ima_canonical_fmt; + /* Internal IMA function definitions */ int ima_init(void); int ima_fs_init(void); @@ -122,7 +148,12 @@ int ima_init_crypto(void); void ima_putc(struct seq_file *m, void *data, int datalen); void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); struct ima_template_desc *ima_template_desc_current(void); +int ima_restore_measurement_entry(struct ima_template_entry *entry); +int ima_restore_measurement_list(loff_t bufsize, void *buf); +int ima_measurements_show(struct seq_file *m, void *v); +unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); +void ima_init_template_list(void); /* * used to protect h_table and sha_table diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 4b9b4a4e1b89..1fd9539a969d 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -130,6 +130,7 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len) { struct signature_v2_hdr *sig; + enum hash_algo ret; if (!xattr_value || xattr_len < 2) /* return default hash algo */ @@ -143,7 +144,9 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, return sig->hash_algo; break; case IMA_XATTR_DIGEST_NG: - return xattr_value->digest[0]; + ret = xattr_value->digest[0]; + if (ret < HASH_ALGO__LAST) + return ret; break; case IMA_XATTR_DIGEST: /* this is for backward compatibility */ @@ -165,13 +168,13 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value) { - struct inode *inode = d_backing_inode(dentry); - - if (!inode->i_op->getxattr) - return 0; + ssize_t ret; - return vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value, - 0, GFP_NOFS); + ret = vfs_getxattr_alloc(dentry, XATTR_NAME_IMA, (char **)xattr_value, + 0, GFP_NOFS); + if (ret == -EOPNOTSUPP) + ret = 0; + return ret; } /* @@ -190,12 +193,12 @@ int ima_appraise_measurement(enum ima_hooks func, { static const char op[] = "appraise_data"; char *cause = "unknown"; - struct dentry *dentry = file->f_path.dentry; + struct dentry *dentry = file_dentry(file); struct inode *inode = d_backing_inode(dentry); enum integrity_status status = INTEGRITY_UNKNOWN; int rc = xattr_len, hash_start = 0; - if (!inode->i_op->getxattr) + if (!(inode->i_opflags & IOP_XATTR)) return INTEGRITY_UNKNOWN; if (rc <= 0) { @@ -295,7 +298,7 @@ out: */ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file) { - struct dentry *dentry = file->f_path.dentry; + struct dentry *dentry = file_dentry(file); int rc = 0; /* do not collect and update hash for digital signatures */ @@ -322,10 +325,10 @@ void ima_inode_post_setattr(struct dentry *dentry) { struct inode *inode = d_backing_inode(dentry); struct integrity_iint_cache *iint; - int must_appraise, rc; + int must_appraise; if (!(ima_policy_flag & IMA_APPRAISE) || !S_ISREG(inode->i_mode) - || !inode->i_op->removexattr) + || !(inode->i_opflags & IOP_XATTR)) return; must_appraise = ima_must_appraise(inode, MAY_ACCESS, POST_SETATTR); @@ -338,8 +341,7 @@ void ima_inode_post_setattr(struct dentry *dentry) iint->flags |= IMA_APPRAISE; } if (!must_appraise) - rc = inode->i_op->removexattr(dentry, XATTR_NAME_IMA); - return; + __vfs_removexattr(dentry, XATTR_NAME_IMA); } /* @@ -385,14 +387,10 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, result = ima_protect_xattr(dentry, xattr_name, xattr_value, xattr_value_len); if (result == 1) { - bool digsig; - if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) return -EINVAL; - digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG); - if (!digsig && (ima_appraise & IMA_APPRAISE_ENFORCE)) - return -EPERM; - ima_reset_appraise_flags(d_backing_inode(dentry), digsig); + ima_reset_appraise_flags(d_backing_inode(dentry), + (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0); result = 0; } return result; diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c index 38f2ed830dd6..802d5d20f36f 100644 --- a/security/integrity/ima/ima_crypto.c +++ b/security/integrity/ima/ima_crypto.c @@ -477,11 +477,13 @@ static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 }; u8 *data_to_hash = field_data[i].data; u32 datalen = field_data[i].len; + u32 datalen_to_hash = + !ima_canonical_fmt ? datalen : cpu_to_le32(datalen); if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) { rc = crypto_shash_update(shash, - (const u8 *) &field_data[i].len, - sizeof(field_data[i].len)); + (const u8 *) &datalen_to_hash, + sizeof(datalen_to_hash)); if (rc) break; } else if (strcmp(td->fields[i]->field_id, "n") == 0) { diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index c07a3844ea0a..ca303e5d2b94 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -28,6 +28,16 @@ static DEFINE_MUTEX(ima_write_mutex); +bool ima_canonical_fmt; +static int __init default_canonical_fmt_setup(char *str) +{ +#ifdef __BIG_ENDIAN + ima_canonical_fmt = 1; +#endif + return 1; +} +__setup("ima_canonical_fmt", default_canonical_fmt_setup); + static int valid_policy = 1; #define TMPBUFLEN 12 static ssize_t ima_show_htable_value(char __user *buf, size_t count, @@ -116,13 +126,13 @@ void ima_putc(struct seq_file *m, void *data, int datalen) * [eventdata length] * eventdata[n]=template specific data */ -static int ima_measurements_show(struct seq_file *m, void *v) +int ima_measurements_show(struct seq_file *m, void *v) { /* the list never shrinks, so we don't need a lock here */ struct ima_queue_entry *qe = v; struct ima_template_entry *e; char *template_name; - int namelen; + u32 pcr, namelen, template_data_len; /* temporary fields */ bool is_ima_template = false; int i; @@ -139,25 +149,29 @@ static int ima_measurements_show(struct seq_file *m, void *v) * PCR used defaults to the same (config option) in * little-endian format, unless set in policy */ - ima_putc(m, &e->pcr, sizeof(e->pcr)); + pcr = !ima_canonical_fmt ? e->pcr : cpu_to_le32(e->pcr); + ima_putc(m, &pcr, sizeof(e->pcr)); /* 2nd: template digest */ ima_putc(m, e->digest, TPM_DIGEST_SIZE); /* 3rd: template name size */ - namelen = strlen(template_name); + namelen = !ima_canonical_fmt ? strlen(template_name) : + cpu_to_le32(strlen(template_name)); ima_putc(m, &namelen, sizeof(namelen)); /* 4th: template name */ - ima_putc(m, template_name, namelen); + ima_putc(m, template_name, strlen(template_name)); /* 5th: template length (except for 'ima' template) */ if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0) is_ima_template = true; - if (!is_ima_template) - ima_putc(m, &e->template_data_len, - sizeof(e->template_data_len)); + if (!is_ima_template) { + template_data_len = !ima_canonical_fmt ? e->template_data_len : + cpu_to_le32(e->template_data_len); + ima_putc(m, &template_data_len, sizeof(e->template_data_len)); + } /* 6th: template specific data */ for (i = 0; i < e->template_desc->num_fields; i++) { @@ -401,7 +415,7 @@ static int ima_release_policy(struct inode *inode, struct file *file) const char *cause = valid_policy ? "completed" : "failed"; if ((file->f_flags & O_ACCMODE) == O_RDONLY) - return 0; + return seq_release(inode, file); if (valid_policy && ima_check_policy() < 0) { cause = "failed"; diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c index 32912bd54ead..2967d497a665 100644 --- a/security/integrity/ima/ima_init.c +++ b/security/integrity/ima/ima_init.c @@ -115,7 +115,8 @@ int __init ima_init(void) ima_used_chip = 1; if (!ima_used_chip) - pr_info("No TPM chip found, activating TPM-bypass!\n"); + pr_info("No TPM chip found, activating TPM-bypass! (rc=%d)\n", + rc); rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA); if (rc) @@ -128,6 +129,8 @@ int __init ima_init(void) if (rc != 0) return rc; + ima_load_kexec_buffer(); + rc = ima_add_boot_aggregate(); /* boot aggregate must be first entry */ if (rc != 0) return rc; diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c new file mode 100644 index 000000000000..e473eee913cb --- /dev/null +++ b/security/integrity/ima/ima_kexec.c @@ -0,0 +1,168 @@ +/* + * Copyright (C) 2016 IBM Corporation + * + * Authors: + * Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> + * Mimi Zohar <zohar@linux.vnet.ibm.com> + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ +#include <linux/seq_file.h> +#include <linux/vmalloc.h> +#include <linux/kexec.h> +#include "ima.h" + +#ifdef CONFIG_IMA_KEXEC +static int ima_dump_measurement_list(unsigned long *buffer_size, void **buffer, + unsigned long segment_size) +{ + struct ima_queue_entry *qe; + struct seq_file file; + struct ima_kexec_hdr khdr; + int ret = 0; + + /* segment size can't change between kexec load and execute */ + file.buf = vmalloc(segment_size); + if (!file.buf) { + ret = -ENOMEM; + goto out; + } + + file.size = segment_size; + file.read_pos = 0; + file.count = sizeof(khdr); /* reserved space */ + + memset(&khdr, 0, sizeof(khdr)); + khdr.version = 1; + list_for_each_entry_rcu(qe, &ima_measurements, later) { + if (file.count < file.size) { + khdr.count++; + ima_measurements_show(&file, qe); + } else { + ret = -EINVAL; + break; + } + } + + if (ret < 0) + goto out; + + /* + * fill in reserved space with some buffer details + * (eg. version, buffer size, number of measurements) + */ + khdr.buffer_size = file.count; + if (ima_canonical_fmt) { + khdr.version = cpu_to_le16(khdr.version); + khdr.count = cpu_to_le64(khdr.count); + khdr.buffer_size = cpu_to_le64(khdr.buffer_size); + } + memcpy(file.buf, &khdr, sizeof(khdr)); + + print_hex_dump(KERN_DEBUG, "ima dump: ", DUMP_PREFIX_NONE, + 16, 1, file.buf, + file.count < 100 ? file.count : 100, true); + + *buffer_size = file.count; + *buffer = file.buf; +out: + if (ret == -EINVAL) + vfree(file.buf); + return ret; +} + +/* + * Called during kexec_file_load so that IMA can add a segment to the kexec + * image for the measurement list for the next kernel. + * + * This function assumes that kexec_mutex is held. + */ +void ima_add_kexec_buffer(struct kimage *image) +{ + struct kexec_buf kbuf = { .image = image, .buf_align = PAGE_SIZE, + .buf_min = 0, .buf_max = ULONG_MAX, + .top_down = true }; + unsigned long binary_runtime_size; + + /* use more understandable variable names than defined in kbuf */ + void *kexec_buffer = NULL; + size_t kexec_buffer_size; + size_t kexec_segment_size; + int ret; + + /* + * Reserve an extra half page of memory for additional measurements + * added during the kexec load. + */ + binary_runtime_size = ima_get_binary_runtime_size(); + if (binary_runtime_size >= ULONG_MAX - PAGE_SIZE) + kexec_segment_size = ULONG_MAX; + else + kexec_segment_size = ALIGN(ima_get_binary_runtime_size() + + PAGE_SIZE / 2, PAGE_SIZE); + if ((kexec_segment_size == ULONG_MAX) || + ((kexec_segment_size >> PAGE_SHIFT) > totalram_pages / 2)) { + pr_err("Binary measurement list too large.\n"); + return; + } + + ima_dump_measurement_list(&kexec_buffer_size, &kexec_buffer, + kexec_segment_size); + if (!kexec_buffer) { + pr_err("Not enough memory for the kexec measurement buffer.\n"); + return; + } + + kbuf.buffer = kexec_buffer; + kbuf.bufsz = kexec_buffer_size; + kbuf.memsz = kexec_segment_size; + ret = kexec_add_buffer(&kbuf); + if (ret) { + pr_err("Error passing over kexec measurement buffer.\n"); + return; + } + + ret = arch_ima_add_kexec_buffer(image, kbuf.mem, kexec_segment_size); + if (ret) { + pr_err("Error passing over kexec measurement buffer.\n"); + return; + } + + pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n", + kbuf.mem); +} +#endif /* IMA_KEXEC */ + +/* + * Restore the measurement list from the previous kernel. + */ +void ima_load_kexec_buffer(void) +{ + void *kexec_buffer = NULL; + size_t kexec_buffer_size = 0; + int rc; + + rc = ima_get_kexec_buffer(&kexec_buffer, &kexec_buffer_size); + switch (rc) { + case 0: + rc = ima_restore_measurement_list(kexec_buffer_size, + kexec_buffer); + if (rc != 0) + pr_err("Failed to restore the measurement list: %d\n", + rc); + + ima_free_kexec_buffer(); + break; + case -ENOTSUPP: + pr_debug("Restoring the measurement list not supported\n"); + break; + case -ENOENT: + pr_debug("No measurement list to restore\n"); + break; + default: + pr_debug("Error restoring the measurement list: %d\n", rc); + } +} diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 596ef616ac21..50818c60538b 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -228,7 +228,7 @@ static int process_measurement(struct file *file, char *buf, loff_t size, if ((action & IMA_APPRAISE_SUBMASK) || strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) /* read 'security.ima' */ - xattr_len = ima_read_xattr(file->f_path.dentry, &xattr_value); + xattr_len = ima_read_xattr(file_dentry(file), &xattr_value); hash_algo = ima_get_hash_algo(xattr_value, xattr_len); @@ -418,6 +418,7 @@ static int __init init_ima(void) { int error; + ima_init_template_list(); hash_setup(CONFIG_IMA_DEFAULT_HASH); error = ima_init(); if (!error) { diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c index 32f6ac0f96df..d9aa5ab71204 100644 --- a/security/integrity/ima/ima_queue.c +++ b/security/integrity/ima/ima_queue.c @@ -29,6 +29,11 @@ #define AUDIT_CAUSE_LEN_MAX 32 LIST_HEAD(ima_measurements); /* list of all measurements */ +#ifdef CONFIG_IMA_KEXEC +static unsigned long binary_runtime_size; +#else +static unsigned long binary_runtime_size = ULONG_MAX; +#endif /* key: inode (before secure-hashing a file) */ struct ima_h_table ima_htable = { @@ -64,12 +69,32 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value, return ret; } +/* + * Calculate the memory required for serializing a single + * binary_runtime_measurement list entry, which contains a + * couple of variable length fields (e.g template name and data). + */ +static int get_binary_runtime_size(struct ima_template_entry *entry) +{ + int size = 0; + + size += sizeof(u32); /* pcr */ + size += sizeof(entry->digest); + size += sizeof(int); /* template name size field */ + size += strlen(entry->template_desc->name) + 1; + size += sizeof(entry->template_data_len); + size += entry->template_data_len; + return size; +} + /* ima_add_template_entry helper function: - * - Add template entry to measurement list and hash table. + * - Add template entry to the measurement list and hash table, for + * all entries except those carried across kexec. * * (Called with ima_extend_list_mutex held.) */ -static int ima_add_digest_entry(struct ima_template_entry *entry) +static int ima_add_digest_entry(struct ima_template_entry *entry, + bool update_htable) { struct ima_queue_entry *qe; unsigned int key; @@ -85,11 +110,34 @@ static int ima_add_digest_entry(struct ima_template_entry *entry) list_add_tail_rcu(&qe->later, &ima_measurements); atomic_long_inc(&ima_htable.len); - key = ima_hash_key(entry->digest); - hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]); + if (update_htable) { + key = ima_hash_key(entry->digest); + hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]); + } + + if (binary_runtime_size != ULONG_MAX) { + int size; + + size = get_binary_runtime_size(entry); + binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ? + binary_runtime_size + size : ULONG_MAX; + } return 0; } +/* + * Return the amount of memory required for serializing the + * entire binary_runtime_measurement list, including the ima_kexec_hdr + * structure. + */ +unsigned long ima_get_binary_runtime_size(void) +{ + if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr))) + return ULONG_MAX; + else + return binary_runtime_size + sizeof(struct ima_kexec_hdr); +}; + static int ima_pcr_extend(const u8 *hash, int pcr) { int result = 0; @@ -103,8 +151,13 @@ static int ima_pcr_extend(const u8 *hash, int pcr) return result; } -/* Add template entry to the measurement list and hash table, - * and extend the pcr. +/* + * Add template entry to the measurement list and hash table, and + * extend the pcr. + * + * On systems which support carrying the IMA measurement list across + * kexec, maintain the total memory size required for serializing the + * binary_runtime_measurements. */ int ima_add_template_entry(struct ima_template_entry *entry, int violation, const char *op, struct inode *inode, @@ -126,7 +179,7 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation, } } - result = ima_add_digest_entry(entry); + result = ima_add_digest_entry(entry, 1); if (result < 0) { audit_cause = "ENOMEM"; audit_info = 0; @@ -149,3 +202,13 @@ out: op, audit_cause, result, audit_info); return result; } + +int ima_restore_measurement_entry(struct ima_template_entry *entry) +{ + int result = 0; + + mutex_lock(&ima_extend_list_mutex); + result = ima_add_digest_entry(entry, 0); + mutex_unlock(&ima_extend_list_mutex); + return result; +} diff --git a/security/integrity/ima/ima_template.c b/security/integrity/ima/ima_template.c index febd12ed9b55..cebb37c63629 100644 --- a/security/integrity/ima/ima_template.c +++ b/security/integrity/ima/ima_template.c @@ -15,16 +15,20 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/rculist.h> #include "ima.h" #include "ima_template_lib.h" -static struct ima_template_desc defined_templates[] = { +static struct ima_template_desc builtin_templates[] = { {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT}, {.name = "ima-ng", .fmt = "d-ng|n-ng"}, {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"}, {.name = "", .fmt = ""}, /* placeholder for a custom format */ }; +static LIST_HEAD(defined_templates); +static DEFINE_SPINLOCK(template_list); + static struct ima_template_field supported_fields[] = { {.field_id = "d", .field_init = ima_eventdigest_init, .field_show = ima_show_template_digest}, @@ -37,6 +41,7 @@ static struct ima_template_field supported_fields[] = { {.field_id = "sig", .field_init = ima_eventsig_init, .field_show = ima_show_template_sig}, }; +#define MAX_TEMPLATE_NAME_LEN 15 static struct ima_template_desc *ima_template; static struct ima_template_desc *lookup_template_desc(const char *name); @@ -52,6 +57,8 @@ static int __init ima_template_setup(char *str) if (ima_template) return 1; + ima_init_template_list(); + /* * Verify that a template with the supplied name exists. * If not, use CONFIG_IMA_DEFAULT_TEMPLATE. @@ -80,7 +87,7 @@ __setup("ima_template=", ima_template_setup); static int __init ima_template_fmt_setup(char *str) { - int num_templates = ARRAY_SIZE(defined_templates); + int num_templates = ARRAY_SIZE(builtin_templates); if (ima_template) return 1; @@ -91,22 +98,28 @@ static int __init ima_template_fmt_setup(char *str) return 1; } - defined_templates[num_templates - 1].fmt = str; - ima_template = defined_templates + num_templates - 1; + builtin_templates[num_templates - 1].fmt = str; + ima_template = builtin_templates + num_templates - 1; + return 1; } __setup("ima_template_fmt=", ima_template_fmt_setup); static struct ima_template_desc *lookup_template_desc(const char *name) { - int i; - - for (i = 0; i < ARRAY_SIZE(defined_templates); i++) { - if (strcmp(defined_templates[i].name, name) == 0) - return defined_templates + i; + struct ima_template_desc *template_desc; + int found = 0; + + rcu_read_lock(); + list_for_each_entry_rcu(template_desc, &defined_templates, list) { + if ((strcmp(template_desc->name, name) == 0) || + (strcmp(template_desc->fmt, name) == 0)) { + found = 1; + break; + } } - - return NULL; + rcu_read_unlock(); + return found ? template_desc : NULL; } static struct ima_template_field *lookup_template_field(const char *field_id) @@ -142,9 +155,14 @@ static int template_desc_init_fields(const char *template_fmt, { const char *template_fmt_ptr; struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX]; - int template_num_fields = template_fmt_size(template_fmt); + int template_num_fields; int i, len; + if (num_fields && *num_fields > 0) /* already initialized? */ + return 0; + + template_num_fields = template_fmt_size(template_fmt); + if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) { pr_err("format string '%s' contains too many fields\n", template_fmt); @@ -182,11 +200,28 @@ static int template_desc_init_fields(const char *template_fmt, return 0; } +void ima_init_template_list(void) +{ + int i; + + if (!list_empty(&defined_templates)) + return; + + spin_lock(&template_list); + for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) { + list_add_tail_rcu(&builtin_templates[i].list, + &defined_templates); + } + spin_unlock(&template_list); +} + struct ima_template_desc *ima_template_desc_current(void) { - if (!ima_template) + if (!ima_template) { + ima_init_template_list(); ima_template = lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE); + } return ima_template; } @@ -205,3 +240,239 @@ int __init ima_init_template(void) return result; } + +static struct ima_template_desc *restore_template_fmt(char *template_name) +{ + struct ima_template_desc *template_desc = NULL; + int ret; + + ret = template_desc_init_fields(template_name, NULL, NULL); + if (ret < 0) { + pr_err("attempting to initialize the template \"%s\" failed\n", + template_name); + goto out; + } + + template_desc = kzalloc(sizeof(*template_desc), GFP_KERNEL); + if (!template_desc) + goto out; + + template_desc->name = ""; + template_desc->fmt = kstrdup(template_name, GFP_KERNEL); + if (!template_desc->fmt) + goto out; + + spin_lock(&template_list); + list_add_tail_rcu(&template_desc->list, &defined_templates); + spin_unlock(&template_list); +out: + return template_desc; +} + +static int ima_restore_template_data(struct ima_template_desc *template_desc, + void *template_data, + int template_data_size, + struct ima_template_entry **entry) +{ + struct binary_field_data { + u32 len; + u8 data[0]; + } __packed; + + struct binary_field_data *field_data; + int offset = 0; + int ret = 0; + int i; + + *entry = kzalloc(sizeof(**entry) + + template_desc->num_fields * sizeof(struct ima_field_data), + GFP_NOFS); + if (!*entry) + return -ENOMEM; + + (*entry)->template_desc = template_desc; + for (i = 0; i < template_desc->num_fields; i++) { + field_data = template_data + offset; + + /* Each field of the template data is prefixed with a length. */ + if (offset > (template_data_size - sizeof(*field_data))) { + pr_err("Restoring the template field failed\n"); + ret = -EINVAL; + break; + } + offset += sizeof(*field_data); + + if (ima_canonical_fmt) + field_data->len = le32_to_cpu(field_data->len); + + if (offset > (template_data_size - field_data->len)) { + pr_err("Restoring the template field data failed\n"); + ret = -EINVAL; + break; + } + offset += field_data->len; + + (*entry)->template_data[i].len = field_data->len; + (*entry)->template_data_len += sizeof(field_data->len); + + (*entry)->template_data[i].data = + kzalloc(field_data->len + 1, GFP_KERNEL); + if (!(*entry)->template_data[i].data) { + ret = -ENOMEM; + break; + } + memcpy((*entry)->template_data[i].data, field_data->data, + field_data->len); + (*entry)->template_data_len += field_data->len; + } + + if (ret < 0) { + ima_free_template_entry(*entry); + *entry = NULL; + } + + return ret; +} + +/* Restore the serialized binary measurement list without extending PCRs. */ +int ima_restore_measurement_list(loff_t size, void *buf) +{ + struct binary_hdr_v1 { + u32 pcr; + u8 digest[TPM_DIGEST_SIZE]; + u32 template_name_len; + char template_name[0]; + } __packed; + char template_name[MAX_TEMPLATE_NAME_LEN]; + + struct binary_data_v1 { + u32 template_data_size; + char template_data[0]; + } __packed; + + struct ima_kexec_hdr *khdr = buf; + struct binary_hdr_v1 *hdr_v1; + struct binary_data_v1 *data_v1; + + void *bufp = buf + sizeof(*khdr); + void *bufendp; + struct ima_template_entry *entry; + struct ima_template_desc *template_desc; + unsigned long count = 0; + int ret = 0; + + if (!buf || size < sizeof(*khdr)) + return 0; + + if (ima_canonical_fmt) { + khdr->version = le16_to_cpu(khdr->version); + khdr->count = le64_to_cpu(khdr->count); + khdr->buffer_size = le64_to_cpu(khdr->buffer_size); + } + + if (khdr->version != 1) { + pr_err("attempting to restore a incompatible measurement list"); + return -EINVAL; + } + + if (khdr->count > ULONG_MAX - 1) { + pr_err("attempting to restore too many measurements"); + return -EINVAL; + } + + /* + * ima kexec buffer prefix: version, buffer size, count + * v1 format: pcr, digest, template-name-len, template-name, + * template-data-size, template-data + */ + bufendp = buf + khdr->buffer_size; + while ((bufp < bufendp) && (count++ < khdr->count)) { + hdr_v1 = bufp; + if (bufp > (bufendp - sizeof(*hdr_v1))) { + pr_err("attempting to restore partial measurement\n"); + ret = -EINVAL; + break; + } + bufp += sizeof(*hdr_v1); + + if (ima_canonical_fmt) + hdr_v1->template_name_len = + le32_to_cpu(hdr_v1->template_name_len); + + if ((hdr_v1->template_name_len >= MAX_TEMPLATE_NAME_LEN) || + (bufp > (bufendp - hdr_v1->template_name_len))) { + pr_err("attempting to restore a template name \ + that is too long\n"); + ret = -EINVAL; + break; + } + data_v1 = bufp += (u_int8_t)hdr_v1->template_name_len; + + /* template name is not null terminated */ + memcpy(template_name, hdr_v1->template_name, + hdr_v1->template_name_len); + template_name[hdr_v1->template_name_len] = 0; + + if (strcmp(template_name, "ima") == 0) { + pr_err("attempting to restore an unsupported \ + template \"%s\" failed\n", template_name); + ret = -EINVAL; + break; + } + + template_desc = lookup_template_desc(template_name); + if (!template_desc) { + template_desc = restore_template_fmt(template_name); + if (!template_desc) + break; + } + + /* + * Only the running system's template format is initialized + * on boot. As needed, initialize the other template formats. + */ + ret = template_desc_init_fields(template_desc->fmt, + &(template_desc->fields), + &(template_desc->num_fields)); + if (ret < 0) { + pr_err("attempting to restore the template fmt \"%s\" \ + failed\n", template_desc->fmt); + ret = -EINVAL; + break; + } + + if (bufp > (bufendp - sizeof(data_v1->template_data_size))) { + pr_err("restoring the template data size failed\n"); + ret = -EINVAL; + break; + } + bufp += (u_int8_t) sizeof(data_v1->template_data_size); + + if (ima_canonical_fmt) + data_v1->template_data_size = + le32_to_cpu(data_v1->template_data_size); + + if (bufp > (bufendp - data_v1->template_data_size)) { + pr_err("restoring the template data failed\n"); + ret = -EINVAL; + break; + } + bufp += data_v1->template_data_size; + + ret = ima_restore_template_data(template_desc, + data_v1->template_data, + data_v1->template_data_size, + &entry); + if (ret < 0) + break; + + memcpy(entry->digest, hdr_v1->digest, TPM_DIGEST_SIZE); + entry->pcr = + !ima_canonical_fmt ? hdr_v1->pcr : le32_to_cpu(hdr_v1->pcr); + ret = ima_restore_measurement_entry(entry); + if (ret < 0) + break; + + } + return ret; +} diff --git a/security/integrity/ima/ima_template_lib.c b/security/integrity/ima/ima_template_lib.c index f9bae04ba176..f9ba37b3928d 100644 --- a/security/integrity/ima/ima_template_lib.c +++ b/security/integrity/ima/ima_template_lib.c @@ -103,8 +103,11 @@ static void ima_show_template_data_binary(struct seq_file *m, u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ? strlen(field_data->data) : field_data->len; - if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) - ima_putc(m, &len, sizeof(len)); + if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) { + u32 field_len = !ima_canonical_fmt ? len : cpu_to_le32(len); + + ima_putc(m, &field_len, sizeof(field_len)); + } if (!len) return; |