From: Roberto Sassu <roberto.sassu@huawei.com> hulk inclusion category: feature feature: IMA Digest Lists extension bugzilla: 46797 ------------------------------------------------- This patch allows direct upload of digest lists by user space parsers. This operation is possible if the digest of the process's executable is found in the digest lists and its type is COMPACT_PARSER. ima_check_measured_appraised() is called at the end of ima_file_check() to verify that everything accessed by the user space parsers (except for directories and securityfs) has been processed by IMA. If a digest list was not processed by an IMA submodule, digest list lookup is disabled for that submodule. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Tianxing Zhang <zhangtianxing3@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Signed-off-by: zhoushuiqing <zhoushuiqing2@huawei.com> --- security/integrity/ima/ima_appraise.c | 2 +- security/integrity/ima/ima_digest_list.c | 56 ++++++++++++++++++++++++ security/integrity/ima/ima_digest_list.h | 18 ++++++++ security/integrity/ima/ima_fs.c | 22 ++++++++++ security/integrity/ima/ima_main.c | 38 +++++++++------- 5 files changed, 119 insertions(+), 17 deletions(-) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 5eca0fb771aa..cdcc20339c8e 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -597,7 +597,7 @@ int ima_appraise_measurement(enum ima_hooks func, /* Allow access to digest lists without metadata, only if they * are signed or found in a digest list (immutable) */ - if (func == DIGEST_LIST_CHECK) { + if (func == DIGEST_LIST_CHECK || ima_current_is_parser()) { if (xattr_value->type == EVM_IMA_XATTR_DIGSIG) break; if (found_digest && diff --git a/security/integrity/ima/ima_digest_list.c b/security/integrity/ima/ima_digest_list.c index 42b2306e43cc..b5d1004e3040 100644 --- a/security/integrity/ima/ima_digest_list.c +++ b/security/integrity/ima/ima_digest_list.c @@ -20,6 +20,8 @@ #include <linux/file.h> #include <linux/namei.h> #include <linux/xattr.h> +#include <linux/sched/mm.h> +#include <linux/magic.h> #include "ima.h" #include "ima_digest_list.h" @@ -216,6 +218,10 @@ void ima_check_measured_appraised(struct file *file) if (!ima_digest_list_actions) return; + if (file_inode(file)->i_sb->s_magic == SECURITYFS_MAGIC || + S_ISDIR(file_inode(file)->i_mode)) + return; + iint = integrity_iint_find(file_inode(file)); if (!iint) { pr_err("%s not processed, disabling digest lists lookup\n", @@ -342,3 +348,53 @@ void __init ima_load_digest_lists(void) out: path_put(&path); } + +/**************** + * Parser check * + ****************/ +bool ima_check_current_is_parser(void) +{ + struct integrity_iint_cache *parser_iint; + struct file *parser_file; + struct mm_struct *mm; + + mm = get_task_mm(current); + if (!mm) + return false; + + parser_file = get_mm_exe_file(mm); + mmput(mm); + + if (!parser_file) + return false; + + parser_iint = integrity_iint_find(file_inode(parser_file)); + fput(parser_file); + + if (!parser_iint) + return false; + + /* flag cannot be cleared due to write protection of executables */ + if (!(parser_iint->flags & IMA_COLLECTED)) + return false; + + return ima_lookup_digest(parser_iint->ima_hash->digest, + parser_iint->ima_hash->algo, COMPACT_PARSER); +} + +struct task_struct *parser_task; + +void ima_set_parser(void) +{ + parser_task = current; +} + +void ima_unset_parser(void) +{ + parser_task = NULL; +} + +bool ima_current_is_parser(void) +{ + return (current == parser_task); +} diff --git a/security/integrity/ima/ima_digest_list.h b/security/integrity/ima/ima_digest_list.h index 5bd2388ff95e..4a8b0e000ad3 100644 --- a/security/integrity/ima/ima_digest_list.h +++ b/security/integrity/ima/ima_digest_list.h @@ -24,6 +24,10 @@ extern struct ima_h_table ima_digests_htable; int ima_parse_compact_list(loff_t size, void *buf, int op); void ima_check_measured_appraised(struct file *file); +bool ima_check_current_is_parser(void); +void ima_set_parser(void); +void ima_unset_parser(void); +bool ima_current_is_parser(void); #else static inline int ima_parse_compact_list(loff_t size, void *buf, int op) { @@ -32,5 +36,19 @@ static inline int ima_parse_compact_list(loff_t size, void *buf, int op) static inline void ima_check_measured_appraised(struct file *file) { } +static inline bool ima_check_current_is_parser(void) +{ + return false; +} +static inline void ima_set_parser(void) +{ +} +static inline void ima_unset_parser(void) +{ +} +static inline bool ima_current_is_parser(void) +{ + return false; +} #endif /*CONFIG_IMA_DIGEST_LIST*/ #endif /*LINUX_IMA_DIGEST_LIST_H*/ diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 2998c3dfbc30..7310683a7af7 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -390,6 +390,20 @@ static ssize_t ima_write_data(struct file *file, const char __user *buf, } else { result = ima_parse_add_rule(data); } + } else if (dentry == digest_list_data) { + if (!ima_current_is_parser()) { + result = -EACCES; + } else { + result = ima_parse_compact_list(datalen, data, + DIGEST_LIST_OP_ADD); + } + } else if (dentry == digest_list_data_del) { + if (!ima_current_is_parser()) { + result = -EACCES; + } else { + result = ima_parse_compact_list(datalen, data, + DIGEST_LIST_OP_DEL); + } } else { pr_err("Unknown data type\n"); result = -EINVAL; @@ -461,6 +475,11 @@ static int ima_open_data_upload(struct inode *inode, struct file *filp) } if (test_and_set_bit(flag, &ima_fs_flags)) return -EBUSY; + + if (dentry == digest_list_data || dentry == digest_list_data_del) + if (ima_check_current_is_parser()) + ima_set_parser(); + return 0; } @@ -480,6 +499,9 @@ static int ima_release_data_upload(struct inode *inode, struct file *file) if ((file->f_flags & O_ACCMODE) == O_RDONLY) return seq_release(inode, file); + if (dentry == digest_list_data || dentry == digest_list_data_del) + ima_unset_parser(); + if (dentry != ima_policy) { clear_bit(flag, &ima_fs_flags); return 0; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 875dbd5d3de9..c6aee92ce68a 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -584,18 +584,18 @@ int ima_file_mprotect(struct vm_area_struct *vma, unsigned long prot) */ int ima_bprm_check(struct linux_binprm *bprm) { - int ret; - u32 secid; + int ret; + u32 secid; - security_current_getsecid_subj(&secid); - ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, - MAY_EXEC, BPRM_CHECK); - if (ret) - return ret; - - security_cred_getsecid(bprm->cred, &secid); - return process_measurement(bprm->file, bprm->cred, secid, NULL, 0, - MAY_EXEC, CREDS_CHECK); + security_current_getsecid_subj(&secid); + ret = process_measurement(bprm->file, current_cred(), secid, NULL, 0, + MAY_EXEC, BPRM_CHECK); + if (ret) + return ret; + + security_cred_getsecid(bprm->cred, &secid); + return process_measurement(bprm->file, bprm->cred, secid, NULL, 0, + MAY_EXEC, CREDS_CHECK); } /** @@ -610,12 +610,18 @@ int ima_bprm_check(struct linux_binprm *bprm) */ int ima_file_check(struct file *file, int mask) { - u32 secid; + int ret; + u32 secid; + int rc; + + security_current_getsecid_subj(&secid); + rc = process_measurement(file, current_cred(), secid, NULL, 0, + mask & (MAY_READ | MAY_WRITE | MAY_EXEC | + MAY_APPEND), FILE_CHECK); + if (ima_current_is_parser() && !rc) + ima_check_measured_appraised(file); + return rc; - security_current_getsecid_subj(&secid); - return process_measurement(file, current_cred(), secid, NULL, 0, - mask & (MAY_READ | MAY_WRITE | MAY_EXEC | - MAY_APPEND), FILE_CHECK); } EXPORT_SYMBOL_GPL(ima_file_check); -- 2.33.0