Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1120f7f4 authored by Sandro's avatar Sandro
Browse files

Create /dev/selinux folder if it was not created by first-stage-init 

The /dev/selinux folder is normally created by first-stage-init
https://cs.android.com/android/platform/superproject/+/master:system/core/init/first_stage_init.cpp;l=299-300;drc=07c86bace1e7a7cc4dd975f10b077d21c3743749

However, in some cases the first-stage-init comes from a GKI prebuilt
boot.img and doess not create the required folder (see for example
b/217677967), resulting in bugs like b/244793900.

I modified the selinux.cpp code to create the /dev/selinux folder if it
does not exist already, as a safety measure.

To verify these changes for b/244793900, follow gpaste/4922166775644160

Bug: 243923977
Test: atest SeamendcHostTest, manual verification
Change-Id: I8fe798643b1aeab2b4caac837055348febf70b94
parent 98e474ab

init/selinux.cpp

+33 −3
Original line number Diff line number Diff line
@@ -525,6 +525,31 @@ const std::vector<std::string> kApexSepolicy{"apex_file_contexts", "apex_propert 
                                             "apex_service_contexts", "apex_seapp_contexts",

                                             "apex_test"};



Result<void> CreateTmpfsDirIfNeeded() {

    mode_t mode = 0744;

    struct stat stat_data;

    if (stat(kTmpfsDir.c_str(), &stat_data) != 0) {

        if (errno != ENOENT) {

            return ErrnoError() << "Could not stat " << kTmpfsDir;

        }

        if (mkdir(kTmpfsDir.c_str(), mode) != 0) {

            return ErrnoError() << "Could not mkdir " << kTmpfsDir;

        }

    } else {

        if (!S_ISDIR(stat_data.st_mode)) {

            return Error() << kTmpfsDir << " exists and is not a directory.";

        }

    }



    // Need to manually call chmod because mkdir will create a folder with

    // permissions mode & ~umask.

    if (chmod(kTmpfsDir.c_str(), mode) != 0) {

        return ErrnoError() << "Could not chmod " << kTmpfsDir;

    }



    return {};

}



Result<void> PutFileInTmpfs(ZipArchiveHandle archive, const std::string& fileName) {

    ZipEntry entry;

    std::string dstPath = kTmpfsDir + fileName;
@@ -538,7 +563,7 @@ Result<void> PutFileInTmpfs(ZipArchiveHandle archive, const std::string& fileNam 
    unique_fd fd(TEMP_FAILURE_RETRY(

            open(dstPath.c_str(), O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, S_IRUSR | S_IWUSR)));

    if (fd == -1) {

        return Error() << "Failed to open " << dstPath;

        return ErrnoError() << "Failed to open " << dstPath;

    }



    ret = ExtractEntryToFile(archive, &entry, fd);
@@ -568,6 +593,11 @@ Result<void> GetPolicyFromApex(const std::string& dir) { 


    auto handle_guard = android::base::make_scope_guard([&handle] { CloseArchive(handle); });



    auto create = CreateTmpfsDirIfNeeded();

    if (!create.ok()) {

        return create.error();

    }



    for (const auto& file : kApexSepolicy) {

        auto extract = PutFileInTmpfs(handle, file);

        if (!extract.ok()) {