CVE-2021-47214 (GCVE-0-2021-47214)
Vulnerability from cvelistv5
Published
2024-04-10 19:01
Modified
2026-05-23 15:19
Severity ?
Summary
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.
References
Impacted products
Vendor Product Version
Linux Linux Version: c7b1850dfb41d0b4154aca8dbc04777fbd75616f
Version: c7b1850dfb41d0b4154aca8dbc04777fbd75616f
Version: 515b6124df6a84c957c5cc6bb6e8309dae7b1e9c
Version: 5.13.13   ≤
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