kernel: userfaultfd: fix a race between writeprotect and exit_mmap()

🗓️ 26 Nov 2024 00:55:09Reported by RedHatType

redhat🔗 access.redhat.com👁 29 Views

The kernel fixes a race between userfaultfd writeprotect and exit_mmap during process exit.

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OS	OS Version	Architecture	Package	Package Version	Filename
Red Hat Enterprise Linux	8.8	aarch64	bpftool	4.18.0-477.81.1.el8_8	bpftool-4.18.0-477.81.1.el8_8.aarch64.rpm
Red Hat Enterprise Linux	8.8	ppc64le	bpftool	4.18.0-477.81.1.el8_8	bpftool-4.18.0-477.81.1.el8_8.ppc64le.rpm
Red Hat Enterprise Linux	8.8	s390x	bpftool	4.18.0-477.81.1.el8_8	bpftool-4.18.0-477.81.1.el8_8.s390x.rpm
Red Hat Enterprise Linux	8.8	x86_64	bpftool	4.18.0-477.81.1.el8_8	bpftool-4.18.0-477.81.1.el8_8.x86_64.rpm
Red Hat Enterprise Linux	8.8	aarch64	bpftool-debuginfo	4.18.0-477.81.1.el8_8	bpftool-debuginfo-4.18.0-477.81.1.el8_8.aarch64.rpm
Red Hat Enterprise Linux	8.8	ppc64le	bpftool-debuginfo	4.18.0-477.81.1.el8_8	bpftool-debuginfo-4.18.0-477.81.1.el8_8.ppc64le.rpm
Red Hat Enterprise Linux	8.8	s390x	bpftool-debuginfo	4.18.0-477.81.1.el8_8	bpftool-debuginfo-4.18.0-477.81.1.el8_8.s390x.rpm
Red Hat Enterprise Linux	8.8	x86_64	bpftool-debuginfo	4.18.0-477.81.1.el8_8	bpftool-debuginfo-4.18.0-477.81.1.el8_8.x86_64.rpm
Red Hat Enterprise Linux	8.8	aarch64	kernel	4.18.0-477.81.1.el8_8	kernel-4.18.0-477.81.1.el8_8.aarch64.rpm
Red Hat Enterprise Linux	8.8	ppc64le	kernel	4.18.0-477.81.1.el8_8	kernel-4.18.0-477.81.1.el8_8.ppc64le.rpm

Source	Link
access	www.access.redhat.com/security/cve/CVE-2021-47461
bugzilla	www.bugzilla.redhat.com/show_bug.cgi
lore	www.lore.kernel.org/linux-cve-announce/2024052225-CVE-2021-47461-a472@gregkh/T
nvd	www.nvd.nist.gov/vuln/detail/CVE-2021-47461
cve	www.cve.org/CVERecord

01 Oct 2026 00:07Current

6.5Medium risk

Vulners AI Score6.5

CVSS 3.14.7 - 7.8

EPSS0.00174

SSVC

userfaultfd writeprotect exit mmap race condition process exit virtual memory areas