{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-74364", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-74364" ], "published": "2026-08-15T06:04:33Z", "summary": "bpf: Reject exclusive maps as inner maps in map-in-map", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject exclusive maps as inner maps in map-in-map\n\nAn exclusive map (created with excl_prog_hash) is bound to a single\nprogram by hash: check_map_prog_compatibility() refuses to load any\nprogram whose digest does not match map->excl_prog_sha. That check\nonly runs for maps a program references directly, i.e. its used_maps.\nA map reached at runtime through a map-of-maps is never in used_maps,\nand bpf_map_meta_equal() does not consider excl_prog_sha, so an\nexclusive map can be inserted into a non-exclusive outer map and\nthen looked up and mutated by an unrelated program, bypassing the\nexclusivity guarantee.\n\nFor the signed loader this defeats the metadata map exclusivity check\nadded in the signed loader: the cached map->sha[] is validated against\nthe signed hash while another program on a hostile host rewrites the\nfrozen map's contents through the outer map.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.40" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.40" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.40" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.40" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-74364" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/3a0f73d27a8d379a8852a378b3c3208143e3b3b2" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7c58ace08f180f8e249e714d1623388362f9d807" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9a3c3c49c333760c8944dadacbe114c1884546ef" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-17T05:50:24Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.1, "cvss_v3_severity": "High", "scenario": "AV:L - The flaw is reached only through bpf(2) syscalls (BPF_MAP_CREATE, BPF_MAP_UPDATE_ELEM, BPF_PROG_LOAD) and runtime BPF helpers on map-in-map structures, which per kernel guidance is a local attack vector.\nAC:L - Exploitation is a reliable, attacker-controlled sequence (create outer map-of-maps, insert exclusive inner map FD, load program referencing only outer map, lookup/mutate inner map) with no races or layout dependencies.\nPR:L - Triggering the vulnerable map-in-map paths requires local BPF privileges (typically CAP_BPF); per kernel guidance this is Low because CAP_BPF can be obtained by unprivileged users via user namespaces, not only init-namespace root.\nUI:N - No victim interaction is required; a local attacker with BPF access can create the outer map, insert the exclusive inner map, and mutate it through an unrelated loaded program without actions by other users.\nS:U - The impact is bypass of BPF exclusive-map and signed-loader integrity controls within the kernel BPF subsystem, not crossing a VM, container-to-host, or IOMMU security boundary.\nC:H - An unrelated BPF program can bpf_map_lookup_elem() an exclusive inner map via map-in-map indirection and read its full contents, including signed metadata and hashes that must remain confidential to unauthorized programs.\nI:H - The same indirection allows bpf_map_update_elem() on an exclusive map bound to a different program digest, defeating exclusivity and enabling rewrite of signed-loader metadata (map->sha[]) and other protected map state.\nA:N - This is an access-control bypass without memory corruption, use-after-free, or kernel panic; exploitation does not inherently cause crashes, hangs, or denial of kernel availability." } } }