Vulnerability · Published May 22, 2024 · Assigned by Linux
CVE-2021-47461userfaultfd: fix a race between writeprotect and exit_mmap()
High 7.8
In plain English
A high-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.2%top 93.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a race between writeprotect and exit_mmap() A race is possible when a process exits, its VMAs are removed by exit_mmap() and at the same time userfaultfd_writeprotect() is called. The race was detected by KASAN on a development kernel, but it appears to be possible on vanilla kernels as well. Use mmget_not_zero() to prevent the race as done in other userfaultfd operations.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | bpftool | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-abi-stablelists | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-core | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-cross-headers | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-debug | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-debug-core | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-debug-devel | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-debug-modules | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-debug-modules-extra | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-devel | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-doc | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-headers | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-modules | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-modules-extra | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-rt | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-core | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug-core | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug-devel | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug-kvm | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug-modules | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-debug-modules-extra | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-devel | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-kvm | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-modules | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-rt-modules-extra | 4.18.0-553.16.1.rt7.357.el8_10 | ALSA-2024:5102 |
| AlmaLinux:8 | kernel-tools | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-tools-libs | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-zfcpdump | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-zfcpdump-core | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-zfcpdump-devel | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-zfcpdump-modules | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | kernel-zfcpdump-modules-extra | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | perf | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| AlmaLinux:8 | python3-perf | 4.18.0-553.16.1.el8_10 | ALSA-2024:5101 |
| Debian:12 | linux | 5.14.16-1 | DEBIAN-CVE-2021-47461 |
| Debian:13 | linux | 5.14.16-1 | DEBIAN-CVE-2021-47461 |
| Debian:14 | linux | 5.14.16-1 | DEBIAN-CVE-2021-47461 |
| Rocky Linux:8 | kernel | 0:4.18.0-553.16.1.el8_10 | RLSA-2024:5101 |
| Rocky Linux:8 | kernel | 0:4.18.0-553.16.1.el8_10.cloud.0.1 | RXSA-2024:5101 |
| Rocky Linux:8 | kernel-rt | 0:4.18.0-553.16.1.rt7.357.el8_10 | RLSA-2024:5102 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2021-47461 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2021-47461 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | 63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 – before 3cda4bfffd4f755645577aaa9e96a606657b452563b2d4174c4ad1f40b48d7138e71bcb564c1fe03 – before 149958ecd0627a9f1e9c678c25c665400054cd6a63b2d4174c4ad1f40b48d7138e71bcb564c1fe03 – before cb185d5f1ebf900f4ae3bf84cee212e6dd035aca |
| Linux | Linux | 5.7 |