Re: [PATCH 2/3] target: close target_put_sess_cmd() vs.core_tmr_abort_task() race v5

[Nicholas A. Bellinger]

On Tue, 2013-05-14 at 15:04 -0400, Greg Kroah-Hartman wrote:
> On Mon, May 13, 2013 at 04:30:06PM -0400, Joern Engel wrote:
> > It is possible for one thread to to take se_sess->sess_cmd_lock in
> > core_tmr_abort_task() before taking a reference count on
> > se_cmd->cmd_kref, while another thread in target_put_sess_cmd() drops
> > se_cmd->cmd_kref before taking se_sess->sess_cmd_lock.
> > 
> > This introduces kref_put_spinlock_irqsave() and uses it in
> > target_put_sess_cmd() to close the race window.
> > 
> > Signed-off-by: Joern Engel <joern@xxxxxxxxx>
> 
> For the kref.h part, please feel free to add:
> 
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

Applied to target-pending/queue

Since this fixes a real long-standing bug within tcm_qla2xxx code, I'm
adding a CC' to stable as well.

Thanks Joern + Greg-KH!

--nab


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