Re: [PATCH 4.9 STABLE] mm, thp: make do_huge_pmd_wp_page() lock page for testing mapcount

2021-02-26 Thread Sasha Levin
On Fri, Feb 26, 2021 at 05:22:00PM +0100, Vlastimil Babka wrote: Jann reported [1] a race between __split_huge_pmd_locked() and page_trans_huge_map_swapcount() which can result in a page to be reused instead of COWed. This was later assigned CVE-2020-29368. This was fixed by commit c444eb564fb1

[PATCH 4.9 STABLE] mm, thp: make do_huge_pmd_wp_page() lock page for testing mapcount

2021-02-26 Thread Vlastimil Babka
Jann reported [1] a race between __split_huge_pmd_locked() and page_trans_huge_map_swapcount() which can result in a page to be reused instead of COWed. This was later assigned CVE-2020-29368. This was fixed by commit c444eb564fb1 ("mm: thp: make the THP mapcount atomic against