CVE-2021-47461

MediumCVSS 4.7/10Last modified Aug 4, 2026

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 4.7/10CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-362

Affected software

No affected versions have been published.

Timeline

Published
May 22, 2024
Last modified
Aug 4, 2026
NVD status
Modified

Related CVEs from 2021

CVE-2021-474625.5In the Linux kernel, the following vulnerability has been resolved: mm/mempolicy: do not allow illegal MPOL_F_NUMA_BALANCING | MPOL_LOCAL iCVE-2021-474635.5In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: fix NULL page->mapping dereference in page_is_secretmem()CVE-2021-474647.4In the Linux kernel, the following vulnerability has been resolved: audit: fix possible null-pointer dereference in audit_filter_rules FixCVE-2021-474655.5In the Linux kernel, the following vulnerability has been resolved: KVM: PPC: Book3S HV: Fix stack handling in idle_kvm_start_guest() In cCVE-2021-474665.5In the Linux kernel, the following vulnerability has been resolved: mm, slub: fix potential memoryleak in kmem_cache_open() In error path,CVE-2021-474675.3In the Linux kernel, the following vulnerability has been resolved: kunit: fix reference count leak in kfree_at_end The reference countingCVE-2021-474685.5In the Linux kernel, the following vulnerability has been resolved: isdn: mISDN: Fix sleeping function called from invalid context The driCVE-2021-474707.8In the Linux kernel, the following vulnerability has been resolved: mm, slub: fix potential use-after-free in slab_debugfs_fops When sysfsCVE-2021-474715.5In the Linux kernel, the following vulnerability has been resolved: drm: mxsfb: Fix NULL pointer dereference crash on unload The mxsfb->crCVE-2021-474735.5In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Fix a memory leak in an error path of qla2x00_process_elCVE-2021-474747.8In the Linux kernel, the following vulnerability has been resolved: comedi: vmk80xx: fix bulk-buffer overflow The driver is using endpointCVE-2021-474757.8In the Linux kernel, the following vulnerability has been resolved: comedi: vmk80xx: fix transfer-buffer overflows The driver uses endpoin
CVE-2021-47461: Medium severity, CVSS 4.7 | Vulnix