CVE-2021-47461
Medium
Elevated severity or exploit probability.
CVSS base
7.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.2%
7.0th percentile
CISA KEV
Not listed
Weakness / dates
CWE-362
Published 2024-05-22 · modified 2026-08-04
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2024-05-22 — Published (NVD)
- 2026-08-04 — Last modified (NVD)
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
References
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca