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Commit d885890e authored by Jeff Vander Stoep's avatar Jeff Vander Stoep
Browse files

Logd: include app package name in selinux metadata 

Note: denial metadata is currently only included on debug builds.

avc: denied { read } for comm="getprop" name="u:object_r:net_dns_prop:s0"
dev="tmpfs" ino=19605 scontext=u:r:untrusted_app:s0:c164,c256,c512,c768
tcontext=u:object_r:net_dns_prop:s0 tclass=file permissive=0 b/12345678
app=android.selinuxtargetsdkcurrent.cts

Bug: 9496886
Bug: 68016944
Test: cts-tradefed run cts -m CtsSelinuxTargetSdkCurrentTestCases
Change-Id: I1700722a45b75d22f17ba4edc7b95cbaf99fdda8
parent b8716687

logd/LogAudit.cpp

+42 −35
Original line number Diff line number Diff line
@@ -112,7 +112,7 @@ static inline bool hasMetadata(char* str, int str_len) { 
std::map<std::string, std::string> LogAudit::populateDenialMap() {

    std::ifstream bug_file("/system/etc/selinux/selinux_denial_metadata");

    std::string line;

    // allocate a map for the static map pointer in logParse to keep track of,

    // allocate a map for the static map pointer in auditParse to keep track of,

    // this function only runs once

    std::map<std::string, std::string> denial_to_bug;

    if (bug_file.good()) {
@@ -140,7 +140,8 @@ std::string LogAudit::denialParse(const std::string& denial, char terminator, 
    return "";

}



void LogAudit::logParse(const std::string& string, std::string* bug_num) {

void LogAudit::auditParse(const std::string& string, uid_t uid,

                          std::string* bug_num) {

    if (!__android_log_is_debuggable()) {

        bug_num->assign("");

        return;
@@ -162,6 +163,11 @@ void LogAudit::logParse(const std::string& string, std::string* bug_num) { 
    } else {

        bug_num->assign("");

    }



    if (uid >= AID_APP_START && uid <= AID_APP_END) {

        bug_num->append(" app=");

        bug_num->append(android::uidToName(uid));

    }

}



int LogAudit::logPrint(const char* fmt, ...) {
@@ -190,8 +196,27 @@ int LogAudit::logPrint(const char* fmt, ...) { 
    while ((cp = strstr(str, "  "))) {

        memmove(cp, cp + 1, strlen(cp + 1) + 1);

    }

    pid_t pid = getpid();

    pid_t tid = gettid();

    uid_t uid = AID_LOGD;

    static const char pid_str[] = " pid=";

    char* pidptr = strstr(str, pid_str);

    if (pidptr && isdigit(pidptr[sizeof(pid_str) - 1])) {

        cp = pidptr + sizeof(pid_str) - 1;

        pid = 0;

        while (isdigit(*cp)) {

            pid = (pid * 10) + (*cp - '0');

            ++cp;

        }

        tid = pid;

        logbuf->wrlock();

        uid = logbuf->pidToUid(pid);

        logbuf->unlock();

        memmove(pidptr, cp, strlen(cp) + 1);

    }



    bool info = strstr(str, " permissive=1") || strstr(str, " policy loaded ");

    static std::string bug_metadata;

    static std::string denial_metadata;

    if ((fdDmesg >= 0) && initialized) {

        struct iovec iov[4];

        static const char log_info[] = { KMSG_PRIORITY(LOG_INFO) };
@@ -228,8 +253,8 @@ int LogAudit::logPrint(const char* fmt, ...) { 
                    last_info ? sizeof(log_info) : sizeof(log_warning);

                iov[1].iov_base = last_str;

                iov[1].iov_len = strlen(last_str);

                iov[2].iov_base = const_cast<char*>(bug_metadata.c_str());

                iov[2].iov_len = bug_metadata.length();

                iov[2].iov_base = const_cast<char*>(denial_metadata.c_str());

                iov[2].iov_len = denial_metadata.length();

                if (count > 1) {

                    iov[3].iov_base = const_cast<char*>(resume);

                    iov[3].iov_len = strlen(resume);
@@ -249,14 +274,14 @@ int LogAudit::logPrint(const char* fmt, ...) { 
            last_info = info;

        }

        if (count == 0) {

            logParse(str, &bug_metadata);

            auditParse(str, uid, &denial_metadata);

            iov[0].iov_base = info ? const_cast<char*>(log_info)

                                   : const_cast<char*>(log_warning);

            iov[0].iov_len = info ? sizeof(log_info) : sizeof(log_warning);

            iov[1].iov_base = str;

            iov[1].iov_len = strlen(str);

            iov[2].iov_base = const_cast<char*>(bug_metadata.c_str());

            iov[2].iov_len = bug_metadata.length();

            iov[2].iov_base = const_cast<char*>(denial_metadata.c_str());

            iov[2].iov_len = denial_metadata.length();

            iov[3].iov_base = const_cast<char*>(newline);

            iov[3].iov_len = strlen(newline);
@@ -269,9 +294,6 @@ int LogAudit::logPrint(const char* fmt, ...) { 
        return 0;

    }



    pid_t pid = getpid();

    pid_t tid = gettid();

    uid_t uid = AID_LOGD;

    log_time now;



    static const char audit_str[] = " audit(";
@@ -296,29 +318,13 @@ int LogAudit::logPrint(const char* fmt, ...) { 
        now = log_time(CLOCK_REALTIME);

    }



    static const char pid_str[] = " pid=";

    char* pidptr = strstr(str, pid_str);

    if (pidptr && isdigit(pidptr[sizeof(pid_str) - 1])) {

        cp = pidptr + sizeof(pid_str) - 1;

        pid = 0;

        while (isdigit(*cp)) {

            pid = (pid * 10) + (*cp - '0');

            ++cp;

        }

        tid = pid;

        logbuf->wrlock();

        uid = logbuf->pidToUid(pid);

        logbuf->unlock();

        memmove(pidptr, cp, strlen(cp) + 1);

    }



    // log to events



    size_t str_len = strnlen(str, LOGGER_ENTRY_MAX_PAYLOAD);

    if (((fdDmesg < 0) || !initialized) && !hasMetadata(str, str_len))

        logParse(str, &bug_metadata);

    str_len = (str_len + bug_metadata.length() <= LOGGER_ENTRY_MAX_PAYLOAD)

                  ? str_len + bug_metadata.length()

        auditParse(str, uid, &denial_metadata);

    str_len = (str_len + denial_metadata.length() <= LOGGER_ENTRY_MAX_PAYLOAD)

                  ? str_len + denial_metadata.length()

                  : LOGGER_ENTRY_MAX_PAYLOAD;

    size_t message_len = str_len + sizeof(android_log_event_string_t);
@@ -332,9 +338,9 @@ int LogAudit::logPrint(const char* fmt, ...) { 
        event->header.tag = htole32(AUDITD_LOG_TAG);

        event->type = EVENT_TYPE_STRING;

        event->length = htole32(str_len);

        memcpy(event->data, str, str_len - bug_metadata.length());

        memcpy(event->data + str_len - bug_metadata.length(),

               bug_metadata.c_str(), bug_metadata.length());

        memcpy(event->data, str, str_len - denial_metadata.length());

        memcpy(event->data + str_len - denial_metadata.length(),

               denial_metadata.c_str(), denial_metadata.length());



        rc = logbuf->log(

            LOG_ID_EVENTS, now, uid, pid, tid, reinterpret_cast<char*>(event),
@@ -380,7 +386,8 @@ int LogAudit::logPrint(const char* fmt, ...) { 
        prefix_len = LOGGER_ENTRY_MAX_PAYLOAD;

    }

    size_t suffix_len = strnlen(ecomm, LOGGER_ENTRY_MAX_PAYLOAD - prefix_len);

    message_len = str_len + prefix_len + suffix_len + bug_metadata.length() + 2;

    message_len =

        str_len + prefix_len + suffix_len + denial_metadata.length() + 2;



    if (main) {  // begin scope for main buffer

        char newstr[message_len];
@@ -390,7 +397,7 @@ int LogAudit::logPrint(const char* fmt, ...) { 
        strncpy(newstr + 1 + str_len, str, prefix_len);

        strncpy(newstr + 1 + str_len + prefix_len, ecomm, suffix_len);

        strncpy(newstr + 1 + str_len + prefix_len + suffix_len,

                bug_metadata.c_str(), bug_metadata.length());

                denial_metadata.c_str(), denial_metadata.length());



        rc = logbuf->log(LOG_ID_MAIN, now, uid, pid, tid, newstr,

                         (message_len <= USHRT_MAX) ? (unsigned short)message_len

logd/LogAudit.h

+1 −1
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ class LogAudit : public SocketListener { 
    std::map<std::string, std::string> populateDenialMap();

    std::string denialParse(const std::string& denial, char terminator,

                            const std::string& search_term);

    void logParse(const std::string& string, std::string* bug_num);

    void auditParse(const std::string& string, uid_t uid, std::string* bug_num);

    int logPrint(const char* fmt, ...)

        __attribute__((__format__(__printf__, 2, 3)));

};