From: Suren Baghdasaryan <surenb@google.com>
To: stable@vger.kernel.org
Cc: gregkh@linuxfoundation.org, jannh@google.com,
ktkhai@virtuozzo.com, torvalds@linux-foundation.org,
shli@fb.com, namit@vmware.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, kernel-team@android.com,
Suren Baghdasaryan <surenb@google.com>
Subject: [PATCH 0/5] 4.14 backports of fixes for "CoW after fork() issue"
Date: Thu, 1 Apr 2021 11:17:36 -0700 [thread overview]
Message-ID: <20210401181741.168763-1-surenb@google.com> (raw)
We received a report that the copy-on-write issue repored by Jann Horn in
https://bugs.chromium.org/p/project-zero/issues/detail?id=2045 is still
reproducible on 4.14 and 4.19 kernels (the first issue with the reproducer
coded in vmsplice.c). I confirmed this and also that the issue was not
reproducible with 5.10 kernel. I tracked the fix to the following patch
introduced in 5.9 which changes the do_wp_page() logic:
09854ba94c6a 'mm: do_wp_page() simplification'
I backported this patch (#2 in the series) along with 2 prerequisite patches
(#1 and #4) that keep the backports clean and two followup fixes to the main
patch (#3 and #5). I had to skip the following fix:
feb889fb40fa 'mm: don't put pinned pages into the swap cache'
because it uses page_maybe_dma_pinned() which does not exists in earlier
kernels. Because pin_user_pages() does not exist there as well, I *think*
we can safely skip this fix on older kernels, but I would appreciate if
someone could confirm that claim.
The patchset cleanly applies over: stable linux-4.14.y, tag: v4.14.228
Note: 4.14 and 4.19 backports are very similar, so while I backported
only to these two versions I think backports for other versions can be
done easily.
Kirill Tkhai (1):
mm: reuse only-pte-mapped KSM page in do_wp_page()
Linus Torvalds (2):
mm: do_wp_page() simplification
mm: fix misplaced unlock_page in do_wp_page()
Nadav Amit (1):
mm/userfaultfd: fix memory corruption due to writeprotect
Shaohua Li (1):
userfaultfd: wp: add helper for writeprotect check
include/linux/ksm.h | 7 ++++
include/linux/userfaultfd_k.h | 10 ++++++
mm/ksm.c | 30 ++++++++++++++++--
mm/memory.c | 60 ++++++++++++++++-------------------
4 files changed, 73 insertions(+), 34 deletions(-)
--
2.31.0.291.g576ba9dcdaf-goog
next reply other threads:[~2021-04-01 18:17 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 18:17 Suren Baghdasaryan [this message]
2021-04-01 18:17 ` [PATCH 1/5] mm: reuse only-pte-mapped KSM page in do_wp_page() Suren Baghdasaryan
2021-04-01 19:38 ` Greg KH
2021-04-01 19:47 ` Suren Baghdasaryan
2021-04-01 18:17 ` [PATCH 2/5] mm: do_wp_page() simplification Suren Baghdasaryan
2021-04-01 18:17 ` [PATCH 3/5] mm: fix misplaced unlock_page in do_wp_page() Suren Baghdasaryan
2021-04-01 18:17 ` [PATCH 4/5] userfaultfd: wp: add helper for writeprotect check Suren Baghdasaryan
2021-04-01 18:17 ` [PATCH 5/5] mm/userfaultfd: fix memory corruption due to writeprotect Suren Baghdasaryan
2021-04-01 18:59 ` [PATCH 0/5] 4.14 backports of fixes for "CoW after fork() issue" Linus Torvalds
2021-04-01 19:43 ` Suren Baghdasaryan
2021-04-01 23:47 ` Peter Xu
2021-04-02 0:12 ` Suren Baghdasaryan
2021-04-07 13:21 ` Vlastimil Babka
2021-04-07 14:30 ` Peter Xu
2021-04-07 16:07 ` Linus Torvalds
2021-04-07 16:33 ` Suren Baghdasaryan
2021-04-07 17:04 ` Linus Torvalds
2021-04-07 18:47 ` Mikulas Patocka
2021-04-07 19:22 ` Linus Torvalds
2021-04-07 21:53 ` Suren Baghdasaryan
2021-04-21 20:01 ` Suren Baghdasaryan
2021-04-21 21:05 ` Peter Xu
2021-04-21 21:17 ` Suren Baghdasaryan
2021-04-21 23:01 ` Suren Baghdasaryan
2021-04-21 22:59 ` Vlastimil Babka
2021-04-21 23:05 ` Suren Baghdasaryan
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