In the Linux kernel, the following vulnerability has been resolved: bpf: Reject exclusive maps as inner maps in map-in-map An exclusive map (created with excl_prog_hash) is bound to a single program by hash: check_map_prog_compatibility() refuses to load any program whose digest does not match map->excl_prog_sha. That check only runs for maps a program references directly, i.e. its used_maps. A map reached at runtime through a map-of-maps is never in used_maps, and bpf_map_meta_equal() does not consider excl_prog_sha, so an exclusive map can be inserted into a non-exclusive outer map and then looked up and mutated by an unrelated program, bypassing the exclusivity guarantee. For the signed loader this defeats the metadata map exclusivity check added in the signed loader: the cached map->sha[] is validated against the signed hash while another program on a hostile host rewrites the frozen map's contents through the outer map.
History

Sat, 15 Aug 2026 13:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-285
CWE-398

Sat, 15 Aug 2026 06:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf: Reject exclusive maps as inner maps in map-in-map An exclusive map (created with excl_prog_hash) is bound to a single program by hash: check_map_prog_compatibility() refuses to load any program whose digest does not match map->excl_prog_sha. That check only runs for maps a program references directly, i.e. its used_maps. A map reached at runtime through a map-of-maps is never in used_maps, and bpf_map_meta_equal() does not consider excl_prog_sha, so an exclusive map can be inserted into a non-exclusive outer map and then looked up and mutated by an unrelated program, bypassing the exclusivity guarantee. For the signed loader this defeats the metadata map exclusivity check added in the signed loader: the cached map->sha[] is validated against the signed hash while another program on a hostile host rewrites the frozen map's contents through the outer map.
Title bpf: Reject exclusive maps as inner maps in map-in-map
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-15T05:58:46.926Z

Reserved: 2026-08-15T05:44:03.887Z

Link: CVE-2026-74364

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:22:38.037

Modified: 2026-08-15T06:22:38.037

Link: CVE-2026-74364

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-15T13:30:04Z