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, LWN, oss-sec, fulldisc, 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) | buster | 4.19.249-2 | fixed |
buster (security) | 4.19.304-1 | fixed | |
bullseye | 5.10.209-2 | fixed | |
bullseye (security) | 5.10.216-1 | fixed | |
bookworm | 6.1.76-1 | fixed | |
bookworm (security) | 6.1.90-1 | fixed | |
sid, trixie | 6.7.12-1 | 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)