diff options
| -rw-r--r-- | Documentation/ABI/testing/ima_policy | 4 | ||||
| -rw-r--r-- | security/integrity/ima/ima.h | 8 | ||||
| -rw-r--r-- | security/integrity/ima/ima_appraise.c | 33 | ||||
| -rw-r--r-- | security/integrity/ima/ima_main.c | 12 | ||||
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 12 | ||||
| -rw-r--r-- | security/integrity/integrity.h | 1 |
6 files changed, 64 insertions, 6 deletions
diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy index 29ebe9afdac4..29aaedf33246 100644 --- a/Documentation/ABI/testing/ima_policy +++ b/Documentation/ABI/testing/ima_policy @@ -25,6 +25,7 @@ Description: lsm: [[subj_user=] [subj_role=] [subj_type=] [obj_user=] [obj_role=] [obj_type=]] option: [[appraise_type=]] [template=] [permit_directio] + [appraise_flag=] base: func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK][MODULE_CHECK] [FIRMWARE_CHECK] [KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK] @@ -38,6 +39,9 @@ Description: fowner:= decimal value lsm: are LSM specific option: appraise_type:= [imasig] [imasig|modsig] + appraise_flag:= [check_blacklist] + Currently, blacklist check is only for files signed with appended + signature. template:= name of a defined IMA template type (eg, ima-ng). Only valid when action is "measure". pcr:= decimal value diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index a65772ffa427..df4ca482fb53 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -256,6 +256,8 @@ int ima_policy_show(struct seq_file *m, void *v); #define IMA_APPRAISE_KEXEC 0x40 #ifdef CONFIG_IMA_APPRAISE +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr); int ima_appraise_measurement(enum ima_hooks func, struct integrity_iint_cache *iint, struct file *file, const unsigned char *filename, @@ -271,6 +273,12 @@ int ima_read_xattr(struct dentry *dentry, struct evm_ima_xattr_data **xattr_value); #else +static inline int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + return 0; +} + static inline int ima_appraise_measurement(enum ima_hooks func, struct integrity_iint_cache *iint, struct file *file, diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 136ae4e0ee92..300c8d2943c5 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -12,6 +12,7 @@ #include <linux/magic.h> #include <linux/ima.h> #include <linux/evm.h> +#include <keys/system_keyring.h> #include "ima.h" @@ -304,6 +305,38 @@ static int modsig_verify(enum ima_hooks func, const struct modsig *modsig, } /* + * ima_check_blacklist - determine if the binary is blacklisted. + * + * Add the hash of the blacklisted binary to the measurement list, based + * on policy. + * + * Returns -EPERM if the hash is blacklisted. + */ +int ima_check_blacklist(struct integrity_iint_cache *iint, + const struct modsig *modsig, int pcr) +{ + enum hash_algo hash_algo; + const u8 *digest = NULL; + u32 digestsize = 0; + int rc = 0; + + if (!(iint->flags & IMA_CHECK_BLACKLIST)) + return 0; + + if (iint->flags & IMA_MODSIG_ALLOWED && modsig) { + ima_get_modsig_digest(modsig, &hash_algo, &digest, &digestsize); + + rc = is_binary_blacklisted(digest, digestsize); + if ((rc == -EPERM) && (iint->flags & IMA_MEASURE)) + process_buffer_measurement(digest, digestsize, + "blacklisted-hash", NONE, + pcr); + } + + return rc; +} + +/* * ima_appraise_measurement - appraise file measurement * * Call evm_verifyxattr() to verify the integrity of 'security.ima'. diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a26e3ad4e886..d7e987baf127 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -335,10 +335,14 @@ static int process_measurement(struct file *file, const struct cred *cred, xattr_value, xattr_len, modsig, pcr, template_desc); if (rc == 0 && (action & IMA_APPRAISE_SUBMASK)) { - inode_lock(inode); - rc = ima_appraise_measurement(func, iint, file, pathname, - xattr_value, xattr_len, modsig); - inode_unlock(inode); + rc = ima_check_blacklist(iint, modsig, pcr); + if (rc != -EPERM) { + inode_lock(inode); + rc = ima_appraise_measurement(func, iint, file, + pathname, xattr_value, + xattr_len, modsig); + inode_unlock(inode); + } if (!rc) rc = mmap_violation_check(func, file, &pathbuf, &pathname, filename); diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 5380aca2b351..f19a895ad7cd 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -765,8 +765,8 @@ enum { Opt_fsuuid, Opt_uid_eq, Opt_euid_eq, Opt_fowner_eq, Opt_uid_gt, Opt_euid_gt, Opt_fowner_gt, Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt, - Opt_appraise_type, Opt_permit_directio, - Opt_pcr, Opt_template, Opt_err + Opt_appraise_type, Opt_appraise_flag, + Opt_permit_directio, Opt_pcr, Opt_template, Opt_err }; static const match_table_t policy_tokens = { @@ -798,6 +798,7 @@ static const match_table_t policy_tokens = { {Opt_euid_lt, "euid<%s"}, {Opt_fowner_lt, "fowner<%s"}, {Opt_appraise_type, "appraise_type=%s"}, + {Opt_appraise_flag, "appraise_flag=%s"}, {Opt_permit_directio, "permit_directio"}, {Opt_pcr, "pcr=%s"}, {Opt_template, "template=%s"}, @@ -1172,6 +1173,11 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry) else result = -EINVAL; break; + case Opt_appraise_flag: + ima_log_string(ab, "appraise_flag", args[0].from); + if (strstr(args[0].from, "blacklist")) + entry->flags |= IMA_CHECK_BLACKLIST; + break; case Opt_permit_directio: entry->flags |= IMA_PERMIT_DIRECTIO; break; @@ -1500,6 +1506,8 @@ int ima_policy_show(struct seq_file *m, void *v) else seq_puts(m, "appraise_type=imasig "); } + if (entry->flags & IMA_CHECK_BLACKLIST) + seq_puts(m, "appraise_flag=check_blacklist "); if (entry->flags & IMA_PERMIT_DIRECTIO) seq_puts(m, "permit_directio "); rcu_read_unlock(); diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index d9323d31a3a8..73fc286834d7 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -32,6 +32,7 @@ #define EVM_IMMUTABLE_DIGSIG 0x08000000 #define IMA_FAIL_UNVERIFIABLE_SIGS 0x10000000 #define IMA_MODSIG_ALLOWED 0x20000000 +#define IMA_CHECK_BLACKLIST 0x40000000 #define IMA_DO_MASK (IMA_MEASURE | IMA_APPRAISE | IMA_AUDIT | \ IMA_HASH | IMA_APPRAISE_SUBMASK) |