{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93144", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T16:02:15.088Z", "datePublished": "2026-09-17T16:11:42.757Z", "dateUpdated": "2026-10-21T12:52:02.003Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-21T12:52:02.003Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject writes through untrusted BTF pointers\n\ncheck_ptr_to_btf_access() lets program-type btf_struct_access callbacks\nvalidate writes before the default BTF access path rejects non-read\naccesses. That bypasses the read-only policy for untrusted BTF pointers\ncreated by helpers such as bpf_rdonly_cast().\n\nReject non-read accesses through PTR_UNTRUSTED BTF pointers at the\ncommon entry point, before the callback branch to handle all cases." } ], "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 attacker-controlled input is BPF bytecode that calls bpf_rdonly_cast() then STX, submitted via bpf(BPF_PROG_LOAD) in SYSCALL_DEFINE5(bpf) → bpf_prog_load() → bpf_check() → do_check_main() → check_mem_access() → check_ptr_to_btf_access(); no remote protocol carries that untrusted pointer or the store.\nAC:L - A BPF_PROG_TYPE_STRUCT_OPS program attached to bpf_dummy_ops (check_struct_ops_btf_id() sets env->ops to bpf_dummy_ops_btf_struct_access) or a BPF_PROG_TYPE_SCHED_CLS program (tc_cls_act_btf_struct_access) does bpf_rdonly_cast() then a store; the WRITE path ran the callback before the old \"only read is supported\" check. No race.\nPR:L - check_ptr_to_btf_access() returns -EPERM unless env->allow_ptr_leaks (bpf_token_capable(CAP_PERFMON)); STRUCT_OPS also fails is_perfmon_prog_type() without CAP_PERFMON, and add_subprog_and_kfunc() needs env->bpf_capable to emit bpf_rdonly_cast. bpf_token_capable() uses ns_capable() on a delegated token userns, not init-namespace root.\nUI:N - The attacker loads that program with BPF_PROG_LOAD and runs it via BPF_PROG_TEST_RUN (bpf_struct_ops_test_run() → dummy_ops_call_op() for bpf_dummy_ops, or bpf_prog_test_run_skb() for SCHED_CLS). No other user must mount, open a file, or cooperate.\nS:U - bpf_convert_ctx_accesses() leaves PTR_TO_BTF_ID|PTR_UNTRUSTED stores as plain STX (only reads become BPF_PROBE_MEM), so the write corrupts host kernel memory in the same authority as the bpf() caller; this is not a KVM/Xen guest-to-host escape or IOMMU bypass.\nC:H - The accepted STX writes attacker bytes through a bpf_rdonly_cast() pointer (obj__ign skips type checks) at bpf_dummy_ops_state.val, nf_conn.mark, or tcp_sock.snd_cwnd. That type-confused kernel write is a memory-corruption primitive that can be turned into an arbitrary kernel read.\nI:H - bpf_dummy_ops_btf_struct_access() accepts any store within sizeof(struct bpf_dummy_ops_state), and _nf_conntrack_btf_struct_access() accepts nf_conn.mark, on a PTR_UNTRUSTED base from bpf_rdonly_cast(); the JIT emits a plain store to that address, an arbitrary kernel write usable for control-flow hijacking.\nA:H - The same unprobed STX to bpf_rdonly_cast(0, btf_id) or to an out-of-bounds map/stack address page-faults in kernel context during bpf_struct_ops_test_run()/bpf_prog_test_run_skb() and oopses/panics, and the attacker can repeat BPF_PROG_TEST_RUN at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "282de143ead96a5d53331e946f31c977b4610a74", "lessThan": "56f92fecd80419567288b7972caa90107033836e", "status": "affected", "versionType": "git" }, { "version": "282de143ead96a5d53331e946f31c977b4610a74", "lessThan": "c4dc883447ae38c4e22a29cc016046fa65d88994", "status": "affected", "versionType": "git" }, { "version": "282de143ead96a5d53331e946f31c977b4610a74", "lessThan": "644cf4e77c2770d4246f6d12f99bc80d253b0ec6", "status": "affected", "versionType": "git" }, { "version": "282de143ead96a5d53331e946f31c977b4610a74", "lessThan": "19d5566b84ca1af0256d0d0003e1a081580c3ba3", "status": "affected", "versionType": "git" }, { "version": "282de143ead96a5d53331e946f31c977b4610a74", "lessThan": "ac65c710cc643cbc52b899627577357867249530", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/bpf/verifier.c" ], "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.114", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "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": "6.2", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.12.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/56f92fecd80419567288b7972caa90107033836e" }, { "url": "https://git.kernel.org/stable/c/c4dc883447ae38c4e22a29cc016046fa65d88994" }, { "url": "https://git.kernel.org/stable/c/644cf4e77c2770d4246f6d12f99bc80d253b0ec6" }, { "url": "https://git.kernel.org/stable/c/19d5566b84ca1af0256d0d0003e1a081580c3ba3" }, { "url": "https://git.kernel.org/stable/c/ac65c710cc643cbc52b899627577357867249530" } ], "title": "bpf: Reject writes through untrusted BTF pointers", "x_generator": { "engine": "bippy-1.2.0" } } } }