From: Oleg Nesterov Date: Thu, 1 Apr 2010 13:13:57 +0000 (+0200) Subject: oom: fix the unsafe usage of badness() in proc_oom_score() X-Git-Tag: v2.6.34-rc4~91 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b95c35e76b29ba812e5dabdd91592e25ec640e93;p=pandora-kernel.git oom: fix the unsafe usage of badness() in proc_oom_score() proc_oom_score(task) has a reference to task_struct, but that is all. If this task was already released before we take tasklist_lock - we can't use task->group_leader, it points to nowhere - it is not safe to call badness() even if this task is ->group_leader, has_intersects_mems_allowed() assumes it is safe to iterate over ->thread_group list. - even worse, badness() can hit ->signal == NULL Add the pid_alive() check to ensure __unhash_process() was not called. Also, use "task" instead of task->group_leader. badness() should return the same result for any sub-thread. Currently this is not true, but this should be changed anyway. Signed-off-by: Oleg Nesterov Cc: stable@kernel.org Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed