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CVE-2021-47461

MEDIUMCVSS 4.7/10EPSS 0.16%

Last modified

CVE-2021-47461 is a medium-severity vulnerability rated 4.7/10 on the CVSS scale. 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.. EPSS estimates a 0.16% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
4.7/10

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.16%

6.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.7, < 5.10.76—
LinuxLinux Kernel>= 5.11, < 5.14.15—
LinuxLinux Kernel5.15Rc1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-47461?
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.
How severe is CVE-2021-47461?
CVE-2021-47461 has a CVSS score of 4.7/10 (MEDIUM severity). The EPSS model estimates a 0.16% probability of exploitation in the next 30 days.
How do I fix CVE-2021-47461?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST