diff options
Diffstat (limited to 'security/sandbox/linux/launch/SandboxLaunch.cpp')
| -rw-r--r-- | security/sandbox/linux/launch/SandboxLaunch.cpp | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/security/sandbox/linux/launch/SandboxLaunch.cpp b/security/sandbox/linux/launch/SandboxLaunch.cpp index bec94f3c4c..6617ff475d 100644 --- a/security/sandbox/linux/launch/SandboxLaunch.cpp +++ b/security/sandbox/linux/launch/SandboxLaunch.cpp @@ -511,6 +511,8 @@ static pid_t ForkWithFlags(int aFlags) { return ret; } +// Returns true for success, or returns false and sets errno on +// failure. Intended only for procfs pseudo-files. static bool WriteStringToFile(const char* aPath, const char* aStr, const size_t aLen) { int fd = open(aPath, O_WRONLY); @@ -519,6 +521,11 @@ static bool WriteStringToFile(const char* aPath, const char* aStr, } ssize_t written = write(fd, aStr, aLen); if (close(fd) != 0 || written != ssize_t(aLen)) { + // procfs shouldn't ever cause a short write, but ensure that + // errno is set to something distinctive if it does + if (written >= 0) { + errno = EMSGSIZE; + } return false; } return true; @@ -537,6 +544,7 @@ static void ConfigureUserNamespace(uid_t uid, gid_t gid) { len = static_cast<size_t>(SafeSPrintf(buf, "%d %d 1", uid, uid)); MOZ_RELEASE_ASSERT(len < sizeof(buf)); if (!WriteStringToFile("/proc/self/uid_map", buf, len)) { + SANDBOX_LOG_ERRNO("writing /proc/self/uid_map"); MOZ_CRASH("Failed to write /proc/self/uid_map"); } @@ -549,6 +557,7 @@ static void ConfigureUserNamespace(uid_t uid, gid_t gid) { len = static_cast<size_t>(SafeSPrintf(buf, "%d %d 1", gid, gid)); MOZ_RELEASE_ASSERT(len < sizeof(buf)); if (!WriteStringToFile("/proc/self/gid_map", buf, len)) { + SANDBOX_LOG_ERRNO("writing /proc/self/gid_map"); MOZ_CRASH("Failed to write /proc/self/gid_map"); } } @@ -641,6 +650,9 @@ void SandboxLaunch::StartChrootServer() { char msg; ssize_t msgLen = HANDLE_EINTR(read(mChrootServer, &msg, 1)); + if (msgLen < 0) { + SANDBOX_LOG_ERRNO("chroot server couldn't read request"); + } if (msgLen == 0) { // Process exited before chrooting (or chose not to chroot?). _exit(0); @@ -653,7 +665,10 @@ void SandboxLaunch::StartChrootServer() { // exits at the end of this function, and which is always // unwriteable. int rv = chroot("/proc/self/fdinfo"); - MOZ_RELEASE_ASSERT(rv == 0); + if (rv != 0) { + SANDBOX_LOG_ERRNO("chroot"); + MOZ_CRASH("chroot failed"); + } // Drop CAP_SYS_CHROOT ASAP. This must happen before responding; // the main child won't be able to waitpid(), so it could start @@ -664,10 +679,16 @@ void SandboxLaunch::StartChrootServer() { // remove that. (Note: if the process can obtain directory fds, for // example via SandboxBroker, it must be blocked from using fchdir.) rv = chdir("/"); - MOZ_RELEASE_ASSERT(rv == 0); + if (rv != 0) { + SANDBOX_LOG_ERRNO("chdir(\"/\")"); + MOZ_CRASH("chdir(\"/\") failed"); + } msg = kSandboxChrootResponse; msgLen = HANDLE_EINTR(write(mChrootServer, &msg, 1)); + if (msgLen < 0) { + SANDBOX_LOG_ERRNO("chroot server couldn't send response"); + } MOZ_RELEASE_ASSERT(msgLen == 1); _exit(0); } |