| Name | CVE-2021-4218 |
| Description | A flaw was found in the Linux kernel’s implementation of reading the SVC RDMA counters. Reading the counter sysctl panics the system. This flaw allows a local attacker with local access to cause a denial of service while the system reboots. The issue is specific to CentOS/RHEL. |
| 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 | (unstable) | (not affected) | | | |
Notes
- linux <not-affected> (Vulnerable code not present; specific to CentOS/RHEL)
https://bugzilla.redhat.com/show_bug.cgi?id=2048359
Issue is specific to CentOS/RHEL. In mainline, xprtrdma always used copy_to_user()
until the general conversion of sysctls to use a kernel buffer.