Junglewise Threat Intelligence

CVE-2025-71266: Linux Kernel infinite loop in ntfs3 indx_find

CVE-2025-71266 · Severity: medium · CVSS 5.5 · Published 2026-03-18

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability in the Linux kernel's NTFS3 file system driver can allow a local user to crash the system. By providing a specially crafted, malformed file or directory entry, an attacker can trigger an infinite loop that exhausts system memory. This results in a denial-of-service condition, causing the operating system to hang or crash.

Technical details

An infinite loop vulnerability exists in the ntfs3 file system driver within the Linux kernel due to a lack of VCN loop detection and depth limits in the indx_find() function. By manipulating the HAS_SUB_NODE flag in an INDEX_ENTRY and the VCN pointer within a directory's INDEX_ALLOCATION block, a local attacker can cause the kernel to repeatedly read the same block. Each iteration of this loop allocates 4 KB of memory, eventually leading to memory exhaustion and an Out-of-Memory (OOM) crash. The fix involves checking the return value of fnd_push() to ensure the index does not exceed the fnd->nodes array size, returning -EINVAL to break the loop.

Affected products

  • Linux Linux Kernel 5.15 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

  • 2025-12-19: patched: Initial patch committed to mainline kernel tree.
  • 2026-03-18: advisory: CVE-2025-71266 published.

References

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