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vulnerability

Ubuntu: (CVE-2023-53826): linux vulnerability

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
Dec 9, 2025
Added
Dec 11, 2025
Modified
Apr 16, 2026

Description

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].

Solutions

ubuntu-upgrade-linuxubuntu-upgrade-linux-awsubuntu-upgrade-linux-aws-5-15ubuntu-upgrade-linux-aws-5-4ubuntu-upgrade-linux-aws-fipsubuntu-upgrade-linux-azureubuntu-upgrade-linux-azure-5-15ubuntu-upgrade-linux-azure-5-4ubuntu-upgrade-linux-azure-fipsubuntu-upgrade-linux-bluefieldubuntu-upgrade-linux-fipsubuntu-upgrade-linux-gcpubuntu-upgrade-linux-gcp-5-15ubuntu-upgrade-linux-gcp-5-4ubuntu-upgrade-linux-gcp-fipsubuntu-upgrade-linux-gkeubuntu-upgrade-linux-gkeopubuntu-upgrade-linux-hwe-5-15ubuntu-upgrade-linux-hwe-5-4ubuntu-upgrade-linux-ibmubuntu-upgrade-linux-ibm-5-15ubuntu-upgrade-linux-ibm-5-4ubuntu-upgrade-linux-intel-iot-realtimeubuntu-upgrade-linux-intel-iotgubuntu-upgrade-linux-intel-iotg-5-15ubuntu-upgrade-linux-iotubuntu-upgrade-linux-kvmubuntu-upgrade-linux-lowlatencyubuntu-upgrade-linux-lowlatency-hwe-5-15ubuntu-upgrade-linux-nvidiaubuntu-upgrade-linux-nvidia-tegraubuntu-upgrade-linux-nvidia-tegra-5-15ubuntu-upgrade-linux-nvidia-tegra-igxubuntu-upgrade-linux-oracleubuntu-upgrade-linux-oracle-5-15ubuntu-upgrade-linux-oracle-5-4ubuntu-upgrade-linux-raspiubuntu-upgrade-linux-raspi-5-4ubuntu-upgrade-linux-realtimeubuntu-upgrade-linux-riscv-5-15ubuntu-upgrade-linux-xilinx-zynqmp

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.