From: Andrew Morton <akpm@linux-foundation.org>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: linux-mm@kvack.org, Charan Teja Kalla <quic_charante@quicinc.com>
Subject: Re: [PATCH] mm: Migrate high-order folios in swap cache correctly
Date: Thu, 14 Dec 2023 14:11:40 -0800 [thread overview]
Message-ID: <20231214141140.a706ad2abb8f568ca4702303@linux-foundation.org> (raw)
In-Reply-To: <20231214045841.961776-1-willy@infradead.org>
On Thu, 14 Dec 2023 04:58:41 +0000 "Matthew Wilcox (Oracle)" <willy@infradead.org> wrote:
> From: Charan Teja Kalla <quic_charante@quicinc.com>
>
> Large folios occupy N consecutive entries in the swap cache
> instead of using multi-index entries like the page cache.
> However, if a large folio is re-added to the LRU list, it can
> be migrated. The migration code was not aware of the difference
> between the swap cache and the page cache and assumed that a single
> xas_store() would be sufficient.
>
> This leaves potentially many stale pointers to the now-migrated folio
> in the swap cache, which can lead to almost arbitrary data corruption
> in the future. This can also manifest as infinite loops with the
> RCU read lock held.
>
> Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
> [modifications to the changelog & tweaked the fix]
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
I'm thinking
Fixes: 3417013e0d183be ("mm/migrate: Add folio_migrate_mapping()")
hence
Cc: <stable@vger.kernel.org>
And also
Reported-by: Charan Teja Kalla <quic_charante@quicinc.com>
Closes: https://lkml.kernel.org/r/1700569840-17327-1-git-send-email-quic_charante@quicinc.com
next prev parent reply other threads:[~2023-12-14 22:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-14 4:58 [PATCH] mm: Migrate high-order folios in swap cache correctly Matthew Wilcox (Oracle)
2023-12-14 22:11 ` Andrew Morton [this message]
2024-02-06 14:54 ` Charan Teja Kalla
2024-02-07 14:38 ` Charan Teja Kalla
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