Files
docker-cli/components/engine/pkg/libcontainer/security/restrict/restrict.go
Tianon Gravi 71620ac1c0 Update restrict.Restrict to both show the error message when failing to mount /dev/null over /proc/kcore, and to ignore "not exists" errors while doing so (for when CONFIG_PROC_KCORE=n in the kernel)
Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Upstream-commit: d60301edb88a4e182a10cd2becb3795b2dd13fab
Component: engine
2014-05-08 01:03:45 -06:00

27 lines
819 B
Go

// +build linux
package restrict
import (
"fmt"
"os"
"syscall"
"github.com/dotcloud/docker/pkg/system"
)
// This has to be called while the container still has CAP_SYS_ADMIN (to be able to perform mounts).
// However, afterwards, CAP_SYS_ADMIN should be dropped (otherwise the user will be able to revert those changes).
func Restrict(mounts ...string) error {
// remount proc and sys as readonly
for _, dest := range mounts {
if err := system.Mount("", dest, "", syscall.MS_REMOUNT|syscall.MS_RDONLY, ""); err != nil {
return fmt.Errorf("unable to remount %s readonly: %s", dest, err)
}
}
if err := system.Mount("/dev/null", "/proc/kcore", "", syscall.MS_BIND, ""); err != nil && !os.IsNotExist(err) {
return fmt.Errorf("unable to bind-mount /dev/null over /proc/kcore: %s", err)
}
return nil
}