On Tue, Oct 06 2015 at 2:17pm -0400, Mikulas Patocka <mpato...@redhat.com> wrote:
> > > On Mon, 5 Oct 2015, Mike Snitzer wrote: > > > FYI, I've put rebased versions of your 2 patches in my wip branch, see: > > http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/log/?h=wip > > I found a bug in the first patch > (http://git.kernel.org/cgit/linux/kernel/git/snitzer/linux.git/commit/?h=wip&id=2e90df2e9cf482f45be4230152535fdab525fbd8) > > There is this piece of code: > > spin_lock(&bs->rescue_lock); > bio_list_add(&bs->rescue_list, bio); > spin_unlock(&bs->rescue_lock); > queue_work(bs->rescue_workqueue, &bs->rescue_work); > > It is possible that after spin_unlock and before queue_work the bio is > finished by previous workqueue invocation. When the bio is finished, it is > possible that the block device is unloaded and queue_work accesses freed > memory. > > Change the code so that queue_work is executed inside the spinlock: > spin_lock(&bs->rescue_lock); > bio_list_add(&bs->rescue_list, bio); > queue_work(bs->rescue_workqueue, &bs->rescue_work); > spin_unlock(&bs->rescue_lock); OK, but that should get pulled out to a separate stable@ fix that patch you reference builds on. I've adjusted my 'wip' branch accordingly (with placeholder commit that needs revised header, etc). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
