Junglewise Threat Intelligence

CVE-2026-43163: Linux Kernel use-after-free in md/bitmap during array resize

CVE-2026-43163 · Severity: medium · CVSS 4.7 · Published 2026-05-06

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's RAID management component could allow a local user to cause a system crash. The issue occurs during the resizing of storage arrays, where a race condition leads to the system attempting to access memory that has already been freed. This results in a 'General Protection Fault' which impacts the availability of the server or workstation.

Technical details

A use-after-free race condition exists between bitmap_daemon_work() and __bitmap_resize() in the Linux kernel's md (Multiple Device) driver. The daemon iterates over the bitmap storage filemap without proper locking, while the resize path concurrently frees that storage via md_bitmap_file_unmap(). Because the quiesce() function does not stop the md thread, the daemon can access freed pages, triggering a General Protection Fault (GPF) in write_page(). The vulnerability is addressed by ensuring mddev->bitmap_info.mutex is held during the bitmap update to synchronize access. An attacker with local access could exploit this to cause a denial-of-service (system crash).

Affected products

  • Linux Linux Kernel 3.5 to 5.10.252, 5.11 to 5.15.202, 5.16 to 6.1.165, 6.2 to 6.6.128, 6.7 to 6.12.75, 6.13 to 6.18.16, 6.19 to 6.19.6

Timeline

  • 2026-01-20: other: Patch submitted by developer
  • 2026-05-06: disclosed: CVE published
  • 2026-05-06: advisory: NVD advisory published

References

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