From: Mike Kravetz <mike.kravetz@oracle.com>
To: Peter Xu <peterx@redhat.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc: Hugh Dickins <hughd@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrea Arcangeli <aarcange@redhat.com>,
Axel Rasmussen <axelrasmussen@google.com>
Subject: Re: [PATCH 2/2] mm/hugetlb: Fix cow where page writtable in child
Date: Mon, 3 May 2021 13:53:03 -0700 [thread overview]
Message-ID: <c69c12d6-1615-e528-37a7-4776abfc7200@oracle.com> (raw)
In-Reply-To: <20210501144110.8784-3-peterx@redhat.com>
On 5/1/21 7:41 AM, Peter Xu wrote:
> When fork() and copy hugetlb page range, we'll remember to wrprotect src pte if
> needed, however we forget about the child! Without it, the child will be able
> to write to parent's pages when mapped as PROT_READ|PROT_WRITE and MAP_PRIVATE,
> which will cause data corruption in the parent process.
>
> This issue can also be exposed by "memfd_test hugetlbfs" kselftest (if it can
> pass the F_SEAL_FUTURE_WRITE test first, though).
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
> mm/hugetlb.c | 2 ++
> 1 file changed, 2 insertions(+)
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
I think we need to add, "Fixes: 4eae4efa2c29" as this is now in v5.12
--
Mike Kravetz
next prev parent reply other threads:[~2021-05-03 20:53 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-01 14:41 [PATCH 0/2] mm/hugetlb: Fix issues on file sealing and fork Peter Xu
2021-05-01 14:41 ` [PATCH 1/2] mm/hugetlb: Fix F_SEAL_FUTURE_WRITE Peter Xu
2021-05-03 18:55 ` Mike Kravetz
2021-05-03 21:31 ` Peter Xu
2021-05-03 22:28 ` Mike Kravetz
2021-05-01 14:41 ` [PATCH 2/2] mm/hugetlb: Fix cow where page writtable in child Peter Xu
2021-05-03 20:53 ` Mike Kravetz [this message]
2021-05-03 21:41 ` Peter Xu
2021-05-03 22:10 ` Mike Kravetz
2021-05-03 22:24 ` Peter Xu
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