Skip to content
Fencer Vulns
no cvss —

CVE-2023-53826 json

ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()

published 2025-12-09 11 mo ago modified 2026-06-17 4 mo ago also EUVD-2023-60170

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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

ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()

Wear-leveling entry could be freed in error path, which may be accessed again in eraseblk_count_seq_show(), for example:

__erase_worker eraseblk_count_seq_show wl = ubi->lookuptbl[*block_number] if (wl) wl_entry_destroy ubi->lookuptbl[e->pnum] = NULL kmem_cache_free(ubi_wl_entry_slab, e) erase_count = wl->ec // UAF!

Wear-leveling entry updating/accessing in ubi->lookuptbl should be protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize wl entry accessing between wl_entry_destroy() and eraseblk_count_seq_show().

Fetch a reproducer in [Link].

Patch / fix

  • Linux Linux 4.14.308, 4.19.276, 5.4.235, 5.10.173, 5.15.100, 6.1.18, 6.2.5, 6.3
  • linux Debian 14, Debian 13, Debian 12 6.1.20-1

debian advisories DEBIAN-CVE-2023-53826

  • linux Ubuntu 20.04 LTS 5.4.0-152.169
  • linux Ubuntu 22.04 LTS 5.15.0-79.86
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1104.112
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1042.47
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1107.116
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1039.47
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1039.44
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1051.56

ubuntu advisories UBUNTU-CVE-2023-53826

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2023-53826 updated cvss 5.5

kernel: ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 10 kernel
    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

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

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.