From: Andrew Morton <akpm@linux-foundation.org>
To: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@kernel.org>, Zi Yan <ziy@nvidia.com>,
Matthew Brost <matthew.brost@intel.com>,
Joshua Hahn <joshua.hahnjy@gmail.com>,
Rakie Kim <rakie.kim@sk.com>, Byungchul Park <byungchul@sk.com>,
Gregory Price <gourry@gourry.net>,
Ying Huang <ying.huang@linux.alibaba.com>,
Alistair Popple <apopple@nvidia.com>, <linux-mm@kvack.org>
Subject: Re: [PATCH] mm: migrate_device: fix pte_pfn/pte_dirty called on non-present PTE
Date: Mon, 6 Jul 2026 11:01:13 -0700 [thread overview]
Message-ID: <20260706110113.920498961e5b29b212c7a199@linux-foundation.org> (raw)
In-Reply-To: <20260706111958.3649651-1-wangkefeng.wang@huawei.com>
On Mon, 6 Jul 2026 19:19:58 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote:
> pte_pfn() and pte_dirty() have undefined behaviour when called on a
> non-present PTE. In migrate_vma_collect_pmd(), these functions may be
> invoked on non-present entries (e.g., swap PTEs), leading to potential
> crashes from pte_pfn() or incorrect dirty folio accounting from
> pte_dirty(). Fix both by guarding with pte_present() checks.
>
> Fixes: fd35ca3d12cc ("mm/migrate_device.c: copy pte dirty bit to page")
> Fixes: a3589e1d5fe3 ("mm/migrate_device.c: add missing flush_cache_page()")
Should we cc:stable?
Sashiko might have found a pre-existing issue:
https://sashiko.dev/#/patchset/20260706111958.3649651-1-wangkefeng.wang@huawei.com
next prev parent reply other threads:[~2026-07-06 18:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-06 11:19 [PATCH] mm: migrate_device: fix pte_pfn/pte_dirty called on non-present PTE Kefeng Wang
2026-07-06 18:01 ` Andrew Morton [this message]
2026-07-07 1:45 ` Zi Yan
2026-07-07 8:00 ` Kefeng Wang
2026-07-07 20:54 ` Zi Yan
2026-07-06 18:30 ` David Hildenbrand (Arm)
2026-07-07 1:28 ` Kefeng Wang
2026-07-07 7:04 ` David Hildenbrand (Arm)
2026-07-07 9:33 ` Kefeng Wang
2026-07-07 13:03 ` David Hildenbrand (Arm)
2026-07-07 14:20 ` Kefeng Wang
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