Re: [PATCH 1/3] signals: fix sigqueue_free() vs __exit_signal()race

From: Andrew Morton
Date: Tue May 20 2008 - 02:34:33 EST


On Sat, 17 May 2008 19:14:18 +0400 Oleg Nesterov <oleg@xxxxxxxxxx> wrote:

> __exit_signal() does flush_sigqueue(tsk->pending) outside of ->siglock.
> This can race with another thread doing sigqueue_free(), we can free
> the same SIGQUEUE_PREALLOC sigqueue twice or corrupt the pending->list.
>
> Note that even sys_exit_group() can trigger this race, not only
> sys_timer_delete().
>
> Move the callsite of flush_sigqueue(tsk->pending) under ->siglock.
>
> This patch doesn't touch flush_sigqueue(->shared_pending) below, it is
> called when there are no other threads which can play with signals,
> and sigqueue_free() can't be used outside of our thread group.

afacit this is the only needed-in-2.6.26 patch from these two
three-patch series, yes?
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