diff options
| author | Kevin Krakauer <krakauer@google.com> | 2020-06-26 16:23:15 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-06-26 16:24:39 -0700 |
| commit | 9cfc15497581824f1c6ba2b9f9ee653d0be0bc5a (patch) | |
| tree | 0d11a48c87597dc08188437f72733de9da0c9024 /pkg | |
| parent | e6a90baef1e6921c560c939f4b591163004613b9 (diff) | |
Require CAP_SYS_ADMIN in the root user namespace for TTY theft
PiperOrigin-RevId: 318563543
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/sentry/kernel/thread_group.go | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/pkg/sentry/kernel/thread_group.go b/pkg/sentry/kernel/thread_group.go index 52849f5b3..4dfd2c990 100644 --- a/pkg/sentry/kernel/thread_group.go +++ b/pkg/sentry/kernel/thread_group.go @@ -366,7 +366,8 @@ func (tg *ThreadGroup) SetControllingTTY(tty *TTY, arg int32) error { // terminal is stolen, and all processes that had it as controlling // terminal lose it." - tty_ioctl(4) if tty.tg != nil && tg.processGroup.session != tty.tg.processGroup.session { - if !auth.CredentialsFromContext(tg.leader).HasCapability(linux.CAP_SYS_ADMIN) || arg != 1 { + // Stealing requires CAP_SYS_ADMIN in the root user namespace. + if creds := auth.CredentialsFromContext(tg.leader); !creds.HasCapabilityIn(linux.CAP_SYS_ADMIN, creds.UserNamespace.Root()) || arg != 1 { return syserror.EPERM } // Steal the TTY away. Unlike TIOCNOTTY, don't send signals. |