CVE-2026-45927

bpf: Require frozen map for calculating map hash

MEDIUM
4.7
CVSS Score
Published: May 27, 2026 at 12:17 PM UTC
Updated: June 27, 2026 at 11:41 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.18 ≤ v < 6.18.146.18 ≤ v < 6.19.46.18 ≤ v < 7.06.19 ≤ v < 6.19.46.18ea2e6467ac36bf3d785defc89e58269b15d182f7
Vendor states this is fixed in 7752d36343862323bbeea4ce3adf0ec2ed86e122 (fixed)
Vendor states this is fixed in a2c86aa621c22f2a7e26c654f936d65cfff0aa91 (fixed)
Vendor states this is fixed in f415e114b58fe02c41191e47f24bdabb438daf72 (fixed)
Vendor states this is fixed in 6.18 (unaffected)
Vendor states this is fixed in 6.18.14 (unaffected)
Vendor states this is fixed in 6.19.4 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusUNDERGOING ANALYSIS
CWE
CWE-367

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