{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-90143", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.789Z", "datePublished": "2026-09-17T16:06:39.775Z", "dateUpdated": "2026-10-19T08:58:41.623Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:58:41.623Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: kcm: Hold RCU read lock while running BPF parser\n\nkcm_parse_func_strparser() calls bpf_prog_run_pin_on_cpu() which\nprevents CPU migration, but does not establish an RCU read-side\ncritical section. Consequently, BPF map operations can trigger\nWARN_ON_ONCE(!bpf_rcu_lock_held()) when called from the KCM strparser\nprogram.\n\nHold the RCU read lock while running the program." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The missing rcu_read_lock is in kcm_parse_func_strparser(), reached after local socket(AF_KCM) and ioctl(SIOCKCMATTACH) installing the caller's BPF_PROG_TYPE_SOCKET_FILTER via bpf_prog_get_type(). A remote TCP peer can only feed an skb into strp_recv(); map helpers fire regardless of payload, and the BPF program is locally supplied.\nAC:L - kcm_attach() always calls strp_check_rcv(), which queues do_strp_work so parse_msg runs in process context under lock_sock() with BH enabled, so bpf_rcu_lock_held() is false. The attacker loads a SOCKET_FILTER that calls bpf_map_lookup_elem and can delete the same HASH key from their own map fd on another thread.\nPR:L - kcm_create() and kcm_ioctl(SIOCKCMATTACH) have no capable() check, and PF_KCM autoloads via MODULE_ALIAS_NETPROTO. bpf_prog_get_type(..., BPF_PROG_TYPE_SOCKET_FILTER) and HASH/ARRAY maps are the unprivileged types in bpf_prog_load()/map_create(); CAP_BPF in the init namespace is not required when unprivileged BPF is enabled.\nUI:N - The attacker opens their own AF_KCM and TCP sockets, loads their own SOCKET_FILTER, issues SIOCKCMATTACH, and either pre-queues TCP data so strp_check_rcv() runs the parser or writes the TCP peer themselves. No other user must mount a filesystem, open a device, or attach a program.\nS:U - A dangling htab_elem used by kcm_parse_func_strparser() is a host-kernel use-after-free that can escalate privileges inside the same kernel. It does not cross a KVM/Xen guest-host boundary or an IOMMU/DMA domain.\nC:H - bpf_map_lookup_elem() proceeds after WARN_ON_ONCE(!bpf_rcu_lock_held()) and __htab_map_lookup_elem() still returns a pointer. Concurrent htab delete via the attacker's map fd frees or freelist-reuses that htab_elem (bpf_mem_cache_free/pcpu_freelist_push) while the SOCKET_FILTER still reads the map value, disclosing kernel heap.\nI:H - The verifier treats the map-value pointer as writable, so the SOCKET_FILTER can store through the dangling htab_elem after free_htab_elem() reuses it, and bpf_map_update_elem() also runs without RCU from kcm_parse_func_strparser(). That is an arbitrary kernel write via heap reuse, not a bounded overwrite.\nA:H - Use of the dangling htab_elem in do_strp_work oopses or panics the kernel. Independently, bpf_map_lookup_elem()/__htab_map_lookup_elem() hit WARN_ON_ONCE(!bpf_rcu_lock_held()) on the first map helper from kcm_parse_func_strparser(), which is fatal on kernels booted with panic_on_warn." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/kcm/kcmsock.c" ], "versions": [ { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "37108861cf7bd909d4a372069bcd61c8f489e232", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "3c70d27e792a28bca650ddd8a9aa0fe3591ffec5", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "1d26a6e007d46babc7fa76e5a157dccf86cd55c0", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "b0e94ea63dbdcbfec9beb819cd5f8fa584809ef2", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "21526f8a191a3c50622b8c10bd927870d780eae4", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "292846223eaddba890e40699d2ab82ee5671798c", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "f392affef3c9ce64dfdde794df0579e0a7793440", "status": "affected", "versionType": "git" }, { "version": "9b73896a81dc68a638a011877b7344b252f92276", "lessThan": "b0346dd64e4905291cc9c479f2e6cf1884ced4e6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/kcm/kcmsock.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.270" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.221" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.188" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/37108861cf7bd909d4a372069bcd61c8f489e232" }, { "url": "https://git.kernel.org/stable/c/3c70d27e792a28bca650ddd8a9aa0fe3591ffec5" }, { "url": "https://git.kernel.org/stable/c/1d26a6e007d46babc7fa76e5a157dccf86cd55c0" }, { "url": "https://git.kernel.org/stable/c/b0e94ea63dbdcbfec9beb819cd5f8fa584809ef2" }, { "url": "https://git.kernel.org/stable/c/21526f8a191a3c50622b8c10bd927870d780eae4" }, { "url": "https://git.kernel.org/stable/c/292846223eaddba890e40699d2ab82ee5671798c" }, { "url": "https://git.kernel.org/stable/c/f392affef3c9ce64dfdde794df0579e0a7793440" }, { "url": "https://git.kernel.org/stable/c/b0346dd64e4905291cc9c479f2e6cf1884ced4e6" } ], "title": "net: kcm: Hold RCU read lock while running BPF parser", "x_generator": { "engine": "bippy-1.2.0" } } } }