diff options
| author | Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> | 2009-04-02 16:58:06 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-04-02 19:04:58 -0700 |
| commit | e4da026f980df125a4918c3bb9fe93185c7ef12a (patch) | |
| tree | bb755bb687bca82feb05ba3bb6962ef57257dd9a /kernel/pid_namespace.c | |
| parent | 921cf9f63089c7442d44083477620132f4cea066 (diff) | |
| download | lwn-e4da026f980df125a4918c3bb9fe93185c7ef12a.tar.gz lwn-e4da026f980df125a4918c3bb9fe93185c7ef12a.zip | |
signals: zap_pid_ns_process() should use force_sig()
send_signal() assumes that signals with SEND_SIG_PRIV are generated from
within the same namespace. So any nested container-init processes become
immune to the SIGKILL generated by kill_proc_info() in
zap_pid_ns_processes().
Use force_sig() in zap_pid_ns_processes() instead - force_sig() clears the
SIGNAL_UNKILLABLE flag ensuring the signal is processed by
container-inits.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/pid_namespace.c')
| -rw-r--r-- | kernel/pid_namespace.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index fab8ea86fac3..2d1001b4858d 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -152,6 +152,7 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) { int nr; int rc; + struct task_struct *task; /* * The last thread in the cgroup-init thread group is terminating. @@ -169,7 +170,19 @@ void zap_pid_ns_processes(struct pid_namespace *pid_ns) read_lock(&tasklist_lock); nr = next_pidmap(pid_ns, 1); while (nr > 0) { - kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr); + rcu_read_lock(); + + /* + * Use force_sig() since it clears SIGNAL_UNKILLABLE ensuring + * any nested-container's init processes don't ignore the + * signal + */ + task = pid_task(find_vpid(nr), PIDTYPE_PID); + if (task) + force_sig(SIGKILL, task); + + rcu_read_unlock(); + nr = next_pidmap(pid_ns, nr); } read_unlock(&tasklist_lock); |