| Name | CVE-2021-47450 |
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Fix host stage-2 PGD refcount The KVM page-table library refcounts the pages of concatenated stage-2 PGDs individually. However, when running KVM in protected mode, the host's stage-2 PGD is currently managed by EL2 as a single high-order compound page, which can cause the refcount of the tail pages to reach 0 when they shouldn't, hence corrupting the page-table. Fix this by introducing a new hyp_split_page() helper in the EL2 page allocator (matching the kernel's split_page() function), and make use of it from host_s2_zalloc_pages_exact(). |
| 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) | jessie, jessie (lts) | 3.16.84-1 | vulnerable |
| stretch (security) | 4.9.320-2 | vulnerable | |
| stretch (lts), stretch | 4.9.320-3 | vulnerable | |
| buster (security), buster, buster (lts) | 4.19.316-1 | fixed | |
| bullseye | 5.10.223-1 | fixed | |
| bullseye (security) | 5.10.226-1 | fixed | |
| bookworm | 6.1.115-1 | fixed | |
| bookworm (security) | 6.1.112-1 | fixed | |
| trixie | 6.11.7-1 | fixed | |
| sid | 6.11.9-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| linux | source | jessie | (unfixed) | end-of-life | ||
| linux | source | stretch | (unfixed) | end-of-life | ||
| linux | source | buster | (not affected) | |||
| linux | source | bullseye | (not affected) | |||
| linux | source | (unstable) | 5.15.3-1 |
[bullseye] - linux <not-affected> (Vulnerable code not present)
[buster] - linux <not-affected> (Vulnerable code not present)
https://git.kernel.org/linus/1d58a17ef54599506d44c45ac95be27273a4d2b1 (5.15)