[patch 15/40] kill sig -1 must only apply to callers namespace

Greg KH
2009-01-23T06:21:51Z

[-- Attachment #1: kill-sig-1-must-only-apply-to-caller-s-namespace.patch --]
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2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>

commit d25141a818383b3c3b09f065698c544a7a0ec6e7 upstream.

Currently "kill <sig> -1" kills processes in all namespaces and breaks the
isolation of namespaces. Earlier attempt to fix this was discussed at:

http://lkml.org/lkml/2008/7/23/148

As suggested by Oleg Nesterov in that thread, use "task_pid_vnr() > 1"
check since task_pid_vnr() returns 0 if process is outside the caller's
namespace.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Tested-by: Daniel Hokka Zakrisson <daniel@hozac.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
kernel/signal.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1141,7 +1141,8 @@ static int kill_something_info(int sig,
struct task_struct * p;

for_each_process(p) {
- if (p->pid > 1 && !same_thread_group(p, current)) {
+ if (task_pid_vnr(p) > 1 &&
+ !same_thread_group(p, current)) {
int err = group_send_sig_info(sig, info, p);
++count;
if (err != -EPERM)