Fixed
Created: Apr 10, 2024
Updated: Apr 20, 2024
Resolved Date: Apr 19, 2024
Found In Version: 10.22.33.1
Severity: Standard
Applicable for: Wind River Linux LTS 22
Component/s: Kernel
In the Linux kernel, the following vulnerability has been resolved:
hugetlb, userfaultfd: fix reservation restore on userfaultfd error
Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error(). In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.
We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error(). Rename new_pagecache_page to
page_in_pagecache to make that clear.
CREATE(Triage):(User=admin) CVE-2021-47214 (https://nvd.nist.gov/vuln/detail/CVE-2021-47214)
