Skip to content
Fencer Vulns
medium 5.5

CVE-2021-47090 json

mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()

published 2024-03-04 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-33738

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()

Hulk Robot reported a panic in put_page_testzero() when testing madvise() with MADV_SOFT_OFFLINE. The BUG() is triggered when retrying get_any_page(). This is because we keep MF_COUNT_INCREASED flag in second try but the refcnt is not increased.

page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) ------------[ cut here ]------------ kernel BUG at include/linux/mm.h:737! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 5 PID: 2135 Comm: sshd Tainted: G B 5.16.0-rc6-dirty #373 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: release_pages+0x53f/0x840 Call Trace: free_pages_and_swap_cache+0x64/0x80 tlb_flush_mmu+0x6f/0x220 unmap_page_range+0xe6c/0x12c0 unmap_single_vma+0x90/0x170 unmap_vmas+0xc4/0x180 exit_mmap+0xde/0x3a0 mmput+0xa3/0x250 do_exit+0x564/0x1470 do_group_exit+0x3b/0x100 __do_sys_exit_group+0x13/0x20 __x64_sys_exit_group+0x16/0x20 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Modules linked in: ---[ end trace e99579b570fe0649 ]--- RIP: 0010:release_pages+0x53f/0x840

Patch / fix

  • Linux Linux 5.10.89, 5.15.12, 5.16
  • linux Debian 14, Debian 13, Debian 12 5.15.15-1

debian advisories DEBIAN-CVE-2021-47090

  • kernel RHEL 8 4.18.0-425.3.1.el8
  • perf RHEL 8 4.18.0-425.3.1.el8
  • bpftool RHEL 8 4.18.0-425.3.1.el8
  • kernel-core RHEL 8 4.18.0-425.3.1.el8
  • kernel-tools RHEL 8 4.18.0-425.3.1.el8
  • python3-perf RHEL 8 4.18.0-425.3.1.el8
  • kernel-modules RHEL 8 4.18.0-425.3.1.el8
  • kernel-zfcpdump RHEL 8 4.18.0-425.3.1.el8

red hat advisories RHSA-2022:7683

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-47090 updated cvss 5.5

kernel: mm/hwpoison: clear MF_COUNT_INCREASED before retrying get_any_page()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +6 more
    affected: no fix available
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-425.3.1.el8, kernel-debuginfo-common-aarch64 4.18.0-425.3.1.el8, kernel-debuginfo-common-ppc64le 4.18.0-425.3.1.el8 Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-425.3.1.el8, kernel 4.18.0-425.3.1.el8, bpftool 4.18.0-425.3.1.el8, kernel-core 4.18.0-425.3.1.el8, kernel-tools 4.18.0-425.3.1.el8, python3-perf 4.18.0-425.3.1.el8, +15 more
    fixed: vendor fix RHSA-2022:7683
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.35% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • git.kernel.org https://git.kernel.org/stable/c/1f207076740101fed87074a6bc924dbe806f08a5 referenced PoC, tagged "exploit" by a source, unverified
  • git.kernel.org https://git.kernel.org/stable/c/c691e7575eff76e563b0199c23ec46bd454f43e3 referenced PoC, tagged "exploit" by a source, unverified
  • git.kernel.org https://git.kernel.org/stable/c/2a57d83c78f889bf3f54eede908d0643c40d5418 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.