When should I use containers versus virtual machines?
What platform should host my containers?
How do I ensure container separation?
How do I secure content inside container?
When should I use containers versus virtual machines?
Drop privileges as quickly as possible
Run your services as non Root whenever possible
Treat root within a container the same as root outside of the container
"Docker is about running random crap from the internet as root on your host"
Only run containers from trusted parties
Everything in Linux is not namespaced
Containers are not comprehensive like virtual machines (kvm)
Kernel file systems: /sys, /sys/fs, /proc/sys
Cgroups, SELinux, /dev/mem, kernel modules
/sys, /proc/sys, /proc/sysrq-trigger,/proc/irq, /proc/bus
man capabilities DESCRIPTION For the purpose of performing permission checks, traditional UNIX implementations distinguish two categories of processes: privileged processes (whose effective user ID is 0, referred to as superuser or root), and unprivileged processes (whose effective UID is nonzero). Privileged processes bypass all kernel permission checks, while unprivileged processes are subject to full permission checking based on the process's credentials (usually: effective UID, effective GID, and supplementary group list). Starting with kernel 2.2, Linux divides the privileges traditionally associated with superuser into distinct units, known as capabilities, which can be independently enabled and disabled. Capabilities are a per-thread attribute.
|CAP_SETPCAP||Modify process capabilities|
|CAP_SYS_MODULE||Insert/Remove kernel modules|
|CAP_SYS_RAWIO||Modify Kernel Memory|
|CAP_SYS_PACCT||Configure process accounting|
|CAP_SYS_NICE||Modify Priotity of processes|
|CAP_SYS_RESOURCE||Override Resource Limits|
|CAP_SYS_TIME||Modify the system clock|
|CAP_SYS_TTY_CONFIG||Configure tty devices|
|CAP_AUDIT_WRITE||Write the audit log|
|CAP_AUDIT_CONTROL||Configure Audit Subsystem|
|CAP_MAC_OVERRIDE||Ignore Kernel MAC Policy|
|CAP_MAC_ADMIN||Configure MAC Configuration|
|CAP_SYSLOG||Modify Kernel printk behavior|
|CAP_NET_ADMIN||Configure the network|
less /usr/include/linux/capability.h ... /* Allow configuration of the secure attention key */ /* Allow administration of the random device */ /* Allow examination and configuration of disk quotas */ /* Allow setting the domainname */ /* Allow setting the hostname */ /* Allow calling bdflush() */ /* Allow mount() and umount(), setting up new smb connection */ /* Allow some autofs root ioctls */ /* Allow nfsservctl */ /* Allow VM86_REQUEST_IRQ */ /* Allow to read/write pci config on alpha */ /* Allow irix_prctl on mips (setstacksize) */ /* Allow flushing all cache on m68k (sys_cacheflush) */ /* Allow removing semaphores */ /* Used instead of CAP_CHOWN to "chown" IPC message queues, semaphores and shared memory */ /* Allow locking/unlocking of shared memory segment */ /* Allow turning swap on/off */ /* Allow forged pids on socket credentials passing */ /* Allow setting readahead and flushing buffers on block devices */
/* Allow setting geometry in floppy driver */ /* Allow turning DMA on/off in xd driver */ /* Allow administration of md devices (mostly the above, but some extra ioctls) */ /* Allow tuning the ide driver */ /* Allow access to the nvram device */ /* Allow administration of apm_bios, serial and bttv (TV) device */ /* Allow manufacturer commands in isdn CAPI support driver */ /* Allow reading non-standardized portions of pci configuration space */ /* Allow DDI debug ioctl on sbpcd driver */ /* Allow setting up serial ports */ /* Allow sending raw qic-117 commands */ /* Allow enabling/disabling tagged queuing on SCSI controllers and sending arbitrary SCSI commands */ /* Allow setting encryption key on loopback filesystem */ /* Allow setting zone reclaim policy */
PID Name Space
Network Name Space
Should have been a namespace
Controls which device nodes can be created within namespace
Device nodes allow processes to configure kernel
images mounted with nodev
SELinux is a LABELING system
Every Process has a LABEL
Every File, Directory, System object has a LABEL
Policy rules control access between labeled processes and labeled objects
The Kernel enforces the rules
Protects the host system from container processes
Container processes can only read/execute /usr files
Container processes only write to container files.
Multi Category Security
Based on Multi Level Security (MLS)
Protects containers from each other.
Container Processes can only read/write their own files.
Docker Daemon picks out unique random MCS Label.
Assigns MCS Label to all content
Launches the container processes with same label
Shrink the attack surface on the kernel
kexec_load, open_by_handle_at, init_module, finit_module, delete_module, iopl, ioperm, swapon, swapoff, sysfs, sysctl, adjtimex, clock_adjtime, lookup_dcookie, perf_event_open, fanotify_init, kcmp
block 32 bit syscalls
block old weird networks
Map non root user to root within container
Currently can protect the host from containers
Goal in the future to protect one container from another?
Biggest Problem lack of file system support
How do you furnish the pigs apartment?
Where did you go to get software?
Go to yahoo.com or AltaVista.com
and google it?
I found it on rpmfind.net, download and install.
Hey I hear there is a big Security vulnerability in Zlib.
How many copies of the Zlib vulnerability to you have?
I have no clue!!!
Red Hat Enterprise Linux solved this problem
Certified software and hardware platforms
Containers move the responsibility for security updates from the Operator to the Developer.
Do you trust developers to
fix security issues in their images?