[SRU Hirsute/Impish 0/1] CVE-2021-4002

[Thadeu Lima de Souza Cascardo]

https://www.openwall.com/lists/oss-security/2021/11/25/1

[Impact]
Missing TLB flush on hugetlb unmapping may allow a different process to
access another process memory, as long as it is using hugetlb mappings.

[Test case]
POC from the link above was used to test it on amd64.

Built tested on other architectures so far. Will test on them as time allows.

[Potential regression]
hugetlb users may regress.

[Notice]
Other backports are in progress and will be tested on other architectures
as well.

Nadav Amit (1):
  hugetlbfs: flush TLBs correctly after huge_pmd_unshare

 mm/hugetlb.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

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2.32.0