| Name | CVE-2021-47214 |
| Description | 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| linux (PTS) | bullseye | 5.10.223-1 | fixed |
| bullseye (security) | 5.10.244-1 | fixed | |
| bookworm | 6.1.148-1 | fixed | |
| bookworm (security) | 6.1.153-1 | fixed | |
| trixie | 6.12.43-1 | fixed | |
| trixie (security) | 6.12.48-1 | fixed | |
| forky | 6.16.12-2 | fixed | |
| sid | 6.17.7-2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| linux | source | buster | (not affected) | |||
| linux | source | bullseye | (not affected) | |||
| linux | source | (unstable) | 5.15.5-1 |
[bullseye] - linux <not-affected> (Vulnerable code not present)
[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/cc30042df6fcc82ea18acf0dace831503e60a0b7 (5.16-rc2)