| Name | CVE-2020-25221 |
| Description | get_gate_page in mm/gup.c in the Linux kernel 5.7.x and 5.8.x before 5.8.7 allows privilege escalation because of incorrect reference counting (caused by gate page mishandling) of the struct page that backs the vsyscall page. The result is a refcount underflow. This can be triggered by any 64-bit process that can use ptrace() or process_vm_readv(), aka CID-9fa2dd946743. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
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) | 5.10.205-2 | fixed |
| bookworm | 6.1.76-1 | fixed |
| bookworm (security) | 6.1.85-1 | fixed |
| trixie | 6.6.15-2 | fixed |
| sid | 6.7.9-2 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| linux | source | stretch | (not affected) | | | |
| linux | source | buster | (not affected) | | | |
| linux | source | (unstable) | 5.8.7-1 | | | |
Notes
[buster] - linux <not-affected> (Vulnerable code introduced later)
[stretch] - linux <not-affected> (Vulnerable code introduced later)
https://git.kernel.org/linus/9fa2dd946743ae6f30dc4830da19147bf100a7f2