We must use a context.Context with a Root Dirent that corresponds to the
container's chroot. Previously we were using the root context, which does not
have a chroot.
Getting the correct context required refactoring some of the path-lookup code.
We can't lookup the path without a context.Context, which requires
kernel.CreateProcArgs, which we only get inside control.Execute. So we have to
do the path lookup much later than we previously were.
PiperOrigin-RevId: 212064734
Change-Id: I84a5cfadacb21fd9c3ab9c393f7e308a40b9b537
This allows applications to verify they are running with gVisor. It
also helps debugging when running with a mix of container runtimes.
Closes#54
PiperOrigin-RevId: 212059457
Change-Id: I51d9595ee742b58c1f83f3902ab2e2ecbd5cedec
It was used before gofer was implemented and it's not
supported anymore.
BREAKING CHANGE: proxy-shared and proxy-exclusive options
are now: shared and exclusive.
PiperOrigin-RevId: 212017643
Change-Id: If029d4073fe60583e5ca25f98abb2953de0d78fd
Before destroying the Kernel, we disable signal forwarding,
relinquishing control to the Go runtime. External signals that arrive
after disabling forwarding but before the sandbox exits thus may use
runtime.raise (i.e., tkill(2)) and violate the syscall filters.
Adjust forwardSignals to handle signals received after disabling
forwarding the same way they are handled before starting forwarding.
i.e., by implementing the standard Go runtime behavior using tgkill(2)
instead of tkill(2).
This also makes the stop callback block until forwarding actually stops.
This isn't required to avoid tkill(2) but is a saner interface.
PiperOrigin-RevId: 211995946
Change-Id: I3585841644409260eec23435cf65681ad41f5f03
We construct a dir with the executable bind-mounted at /exe, and proc mounted
at /proc. Runsc now executes the sandbox process inside this chroot, thus
limiting access to the host filesystem. The mounts and chroot dir are removed
when the sandbox is destroyed.
Because this requires bind-mounts, we can only do the chroot if we have
CAP_SYS_ADMIN.
PiperOrigin-RevId: 211994001
Change-Id: Ia71c515e26085e0b69b833e71691830148bc70d1
Docker and containerd do not expose runsc's stderr, so tracking down sentry
panics can be painful.
If we have a debug log file, we should send panics (and all stderr data) to the
log file.
PiperOrigin-RevId: 211992321
Change-Id: I5f0d2f45f35c110a38dab86bafc695aaba42f7a3
It was always returning the MountNamespace root, which may be different from
the process Root if the process is in a chroot environment.
PiperOrigin-RevId: 211862181
Change-Id: I63bfeb610e2b0affa9fdbdd8147eba3c39014480
Now, we can kill individual containers rather than the entire sandbox.
PiperOrigin-RevId: 211748106
Change-Id: Ic97e91db33d53782f838338c4a6d0aab7a313ead
Now that it's possible to remove subnets, we must iterate over them with locks
held.
Also do the removal more efficiently while I'm here.
PiperOrigin-RevId: 211737416
Change-Id: I29025ec8b0c3ad11f22d4447e8ad473f1c785463
When no capabilities are specified in exec, use the
container's capabilities to match runc's behavior.
PiperOrigin-RevId: 211735186
Change-Id: Icd372ed64410c81144eae94f432dffc9fe3a86ce
Makes it possible to avoid copying or allocating in cases where DeliverNetworkPacket (rx)
needs to turn around and call WritePacket (tx) with its VectorisedView.
Also removes the restriction on having VectorisedViews with multiple views in the write path.
PiperOrigin-RevId: 211728717
Change-Id: Ie03a65ecb4e28bd15ebdb9c69f05eced18fdfcff
With multi-gofers, bind mounts in sub-containers should
just work. Removed restrictions and added test. There are
also a few cleanups along the way, e.g. retry unmounting
in case cleanup races with gofer teardown.
PiperOrigin-RevId: 211699569
Change-Id: Ic0a69c29d7c31cd7e038909cc686c6ac98703374
Remove GetExecutablePath (the non-internal version). This makes path handling
more consistent between exec, root, and child containers.
The new getExecutablePath now uses MountNamespace.FindInode, which is more
robust than Walking the Dirent tree ourselves.
This also removes the last use of lstat(2) in the sentry, so that can be
removed from the filters.
PiperOrigin-RevId: 211683110
Change-Id: Ic8ec960fc1c267aa7d310b8efe6e900c88a9207a
When starting a sandbox without direct file or network access, we create an
empty user namespace and run the sandbox in there. However, the root user in
that namespace is still mapped to the root user in the parent namespace.
This CL maps the "nobody" user from the parent namespace into the child
namespace, and runs the sandbox process as user "nobody" inside the new
namespace.
PiperOrigin-RevId: 211572223
Change-Id: I1b1f9b1a86c0b4e7e5ca7bc93be7d4887678bab6
This is a prereq for running the sandbox process as user "nobody", when it may
not have permissions to open these files.
Instead, we must open then before starting the sandbox process, and pass them
by FD.
The specutils.ReadSpecFromFile method was fixed to always seek to the beginning
of the file before reading. This allows Files from the same FD to be read
multiple times, as we do in the boot command when the apply-caps flag is set.
Tested with --network=host.
PiperOrigin-RevId: 211570647
Change-Id: I685be0a290aa7f70731ebdce82ebc0ebcc9d475c
Furthermore, allow for the specification of an ElementMapper. This allows a
single "Element" type to exist on multiple inline lists, and work without
having to embed the entry type.
This is a requisite change for supporting a per-Inode list of Dirents.
PiperOrigin-RevId: 211467497
Change-Id: If2768999b43e03fdaecf8ed15f435fe37518d163
Task.creds can only be changed by the task's own set*id and execve
syscalls, and Task namespaces can only be changed by the task's own
unshare/setns syscalls.
PiperOrigin-RevId: 211156279
Change-Id: I94d57105d34e8739d964400995a8a5d76306b2a0
From //pkg/sentry/context/context.go:
// - It is *not safe* to retain a Context passed to a function beyond the scope
// of that function call.
Passing a stored kernel.Task as a context.Context to
fs.FileOwnerFromContext violates this requirement.
PiperOrigin-RevId: 211143021
Change-Id: I4c5b02bd941407be4c9cfdbcbdfe5a26acaec037
This allows us to call kernel.FDMap.DecRef without holding mutexes
cleanly.
PiperOrigin-RevId: 211139657
Change-Id: Ie59d5210fb9282e1950e2e40323df7264a01bcec
This CL does NDP link-address discovery for IPv6.
It includes several small changes necessary to get linux to talk to
this implementation. In particular, a hop limit of 255 is necessary
for ICMPv6.
PiperOrigin-RevId: 211103930
Change-Id: If25370ab84c6b1decfb15de917f3b0020f2c4e0e
GoCompile: missing strict dependencies:
/tmpfs/tmp/bazel/sandbox/linux-sandbox/1744/execroot/__main__/runsc/main.go:
import of "gvisor.googlesource.com/gvisor/runsc/specutils"
This was broken in 210995199.
PiperOrigin-RevId: 211086595
Change-Id: I166b9a2ed8e4d6e624def944b720190940d7537c
Nicolas Lacasse
Fabricio Voznika
Adin Scannell
Michael Pratt
Lantao Liu
Kevin Krakauer
Tamir Duberstein
Bert Muthalaly
Brian Geffon
Bhasker Hariharan
Googler
Jamie Liu