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From:   Uladzislau Rezki <urezki@gmail.com>
Date:   Mon, 20 Jun 2022 12:43:59 +0200
Message-ID: <CA+KHdyXpdow7SYsbq_7F0zDd5-nYGi6db7R11R3--g3gUu-59w@mail.gmail.com>
Subject: Re: [PATCH] mm: fix racing of vb->va when kasan enabled
To:     Zhaoyang Huang <huangzhaoyang@gmail.com>
Cc:     "zhaoyang.huang" <zhaoyang.huang@unisoc.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        "open list:MEMORY MANAGEMENT" <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Ke Wang <ke.wang@unisoc.com>, Christoph Hellwig <hch@lst.de>
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> > >
> > Is it easy to reproduce? If so could you please describe the steps? As i see
> > the freeing of the "vb" is RCU safe whereas vb->va is not. But from the first
> > glance i do not see how it can accessed twice. Hm..
> It was raised from a monkey test on A13_k515 system and got 1/20 pcs
> failed. IMO, vb->va which out of vmap_purge_lock protection could race
> with a concurrent ra freeing within __purge_vmap_area_lazy.
>
Do you have exact steps how you run "monkey" test?

-- 
Uladzislau Rezki