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| author | Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> | 2009-09-23 15:57:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-24 07:21:04 -0700 |
| commit | 123be07b0b399670a7cc3d82fef0cb4f93ef885c (patch) | |
| tree | b6edc440be85cf312f7c35ad7b01c7ce7d9241a7 | |
| parent | 8d65af789f3e2cf4cfbdbf71a0f7a61ebcd41d38 (diff) | |
| download | lwn-123be07b0b399670a7cc3d82fef0cb4f93ef885c.tar.gz lwn-123be07b0b399670a7cc3d82fef0cb4f93ef885c.zip | |
fork(): disable CLONE_PARENT for init
When global or container-init processes use CLONE_PARENT, they create a
multi-rooted process tree. Besides siblings of global init remain as
zombies on exit since they are not reaped by their parent (swapper). So
prevent global and container-inits from creating siblings.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Oren Laadan <orenl@cs.columbia.edu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/fork.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index 51ad0b0b7266..b51fd2ccb2f1 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -979,6 +979,16 @@ static struct task_struct *copy_process(unsigned long clone_flags, if ((clone_flags & CLONE_SIGHAND) && !(clone_flags & CLONE_VM)) return ERR_PTR(-EINVAL); + /* + * Siblings of global init remain as zombies on exit since they are + * not reaped by their parent (swapper). To solve this and to avoid + * multi-rooted process trees, prevent global and container-inits + * from creating siblings. + */ + if ((clone_flags & CLONE_PARENT) && + current->signal->flags & SIGNAL_UNKILLABLE) + return ERR_PTR(-EINVAL); + retval = security_task_create(clone_flags); if (retval) goto fork_out; |