CVE-2021-47461
Vulnerability Summary
Timeline
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.
CVSS Metrics
- v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Trends
Current EPSS score: 0.17%• Percentile: 7%
Techniques & Countermeasures
- CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
Affected Systems
- debian•linux
< 5.10.84-1 | < 5.14.16-1 | < 5.14.16-1 | < 5.14.16-1
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-azure
all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-gcp
all
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gke
all
- ubuntu•linux-gke-4.15
all
- ubuntu•linux-gke-5.15
all
- ubuntu•linux-gke-5.4
all
- ubuntu•linux-gkeop-5.4
all
- ubuntu•linux-hwe
all
- ubuntu•linux-hwe-5.11
all
- ubuntu•linux-hwe-5.13
all
- ubuntu•linux-hwe-5.19
all
- ubuntu•linux-hwe-5.8
all
- ubuntu•linux-hwe-6.2
all
- ubuntu•linux-hwe-edge
all | all
- ubuntu•linux-intel-5.13
all
- ubuntu•linux-lowlatency-hwe-5.19
all
- ubuntu•linux-lowlatency-hwe-6.2
all
- ubuntu•linux-nvidia-6.2
all
- ubuntu•linux-oem
all
- ubuntu•linux-oem-5.10
all
- ubuntu•linux-oem-5.13
all
- ubuntu•linux-oem-5.14
all
- ubuntu•linux-oem-5.17
all
- ubuntu•linux-oem-5.6
all
- ubuntu•linux-oem-6.0
all
Showing first 50 affected entries in server-rendered view.
References (7)
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
- https://ubuntu.com/security/CVE-2021-47461
- https://www.cve.org/CVERecord?id=CVE-2021-47461
- https://git.kernel.org/linus/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
- https://security-tracker.debian.org/tracker/CVE-2021-47461