Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected c7b1850dfb41d0b4154aca8dbc04777fbd75616f before b5069d44e2fbc4a9093d005b3ef0949add3dd27e; affected c7b1850dfb41d0b4154aca8dbc04777fbd75616f before cc30042df6fcc82ea18acf0dace831503e60a0b7; affected 515b6124df6a84c957c5cc6bb6e8309dae7b1e9c; affected 5.13.13 before 5.14 |
| Linux / Linux | affected 5.14; unaffected 0 before 5.14; unaffected 5.15.5 through 5.15.*; unaffected 5.16 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/b5069d44e2fbc4a9093d005b3ef0949add3dd27e
- https://git.kernel.org/stable/c/cc30042df6fcc82ea18acf0dace831503e60a0b7
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.