Riskcovery

CVE-2026-45927

bpf: Require frozen map for calculating map hash

State
Published
Severity
Not scored
Published
May 27, 2026
Updated
May 27, 2026
Reserved
May 13, 2026

Read the record on cve.org

Description

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

bpf: Require frozen map for calculating map hash

Currently, bpf_map_get_info_by_fd calculates and caches the hash of the map regardless of the map's frozen state.

This leads to a TOCTOU bug where userspace can call BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map contents before freezing.

Therefore, a trusted loader can be tricked into verifying the stale hash while loading the modified contents.

Fix this by returning -EPERM if the map is not frozen when the hash is requested. This ensures the hash is only generated for the final, immutable state of the map.

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • ea2e6467ac36bf3d785defc89e58269b15d182f7 to before 7752d36343862323bbeea4ce3adf0ec2ed86e122Affected
  • ea2e6467ac36bf3d785defc89e58269b15d182f7 to before f415e114b58fe02c41191e47f24bdabb438daf72Affected
  • ea2e6467ac36bf3d785defc89e58269b15d182f7 to before a2c86aa621c22f2a7e26c654f936d65cfff0aa91Affected
LinuxLinux
  • 6.18Affected
  • before 6.18Not affected
  • 6.18.14 through 6.18.*Not affected
  • 6.19.4 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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