{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-36918", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-30T15:25:07.068Z", "datePublished": "2024-05-30T15:29:13.904Z", "dateUpdated": "2026-08-05T11:32:03.979Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:32:03.979Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check bloom filter map value size\n\nThis patch adds a missing check to bloom filter creating, rejecting\nvalues above KMALLOC_MAX_SIZE. This brings the bloom map in line with\nmany other map types.\n\nThe lack of this protection can cause kernel crashes for value sizes\nthat overflow int's. Such a crash was caught by syzkaller. The next\npatch adds more guard-rails at a lower level." } ], "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 bug is reached purely through the `bpf()` syscall — `BPF_MAP_CREATE` for a bloom-filter map with an oversized `value_size`, then `BPF_PROG_LOAD` of a program calling `bpf_map_push_elem()` on it. No network or remote-peer input is involved.\nAC:L - Triggering is fully deterministic and attacker-controlled: pick any `value_size >= 0x80000000` and any negative stack offset, and the signed overflow in `max_off + access_size` fires every time. There is no race, no timing window, and no memory-layout precondition needed to reach the out-of-bounds loop.\nPR:L - `bpf_map_push_elem` is in the unprivileged section of `bpf_base_func_proto()`, and bloom-filter map creation has no per-map-type capability gate at all on 5.16–6.3 (only `sysctl_unprivileged_bpf_disabled`), while on 6.9 a delegated bpffs BPF token grants `ns_capable(userns, CAP_BPF)` to an unprivileged containerized process. CAP_BPF is a deliberately reduced, non-root privilege routinely held by ordinary service accounts, so a basic low-privileged local context suffices.\nUI:N - The attacker performs the entire sequence — map creation plus program load — from their own process. No other user or administrator has to do anything.\nS:U - The corruption occurs in kernel heap memory belonging to the BPF verifier, within the same security authority as the exploiting process. No hypervisor, IOMMU, or other trust boundary is crossed.\nC:H - The loop performs unbounded negative-index reads of `state->stack[spi].slot_type[]` and `spilled_ptr`, and `mark_reg_read()` chases an out-of-bounds `parent` pointer, giving an out-of-bounds kernel-heap read primitive that a heap-groomed attacker can leverage for arbitrary memory disclosure.\nI:H - With `clobber = true` the loop writes `*stype = STACK_MISC` out of bounds, `__mark_reg_unknown()`/`scrub_spilled_slot()` write a full `bpf_reg_state` and 8-byte slots out of bounds, and `mark_reg_read()` ORs `REG_LIVE_READ64` into an attacker-influenced wild pointer — an out-of-bounds write usable for control-flow hijacking.\nA:H - The overflowed loop iterates roughly two billion times descending ~120 bytes per 8 iterations, so it walks tens of gigabytes below the `stack` allocation and reliably faults on unmapped memory, producing a kernel oops/panic that any local user with map-create access can trigger 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/bloom_filter.c", "tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c" ], "versions": [ { "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "fa6995eeb62e74b5a1480c73fb7b420c270784d3", "status": "affected", "versionType": "git" }, { "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "608e13706c8b6c658a0646f09ebced74ec367f7c", "status": "affected", "versionType": "git" }, { "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "c418afb9bf23e2f2b76cb819601e4a5d9dbab42d", "status": "affected", "versionType": "git" }, { "version": "9330986c03006ab1d33d243b7cfe598a7a3c1baa", "lessThan": "a8d89feba7e54e691ca7c4efc2a6264fa83f3687", "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/bloom_filter.c", "tools/testing/selftests/bpf/prog_tests/bloom_filter_map.c" ], "versions": [ { "version": "5.16", "status": "affected" }, { "version": "0", "lessThan": "5.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.91", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.31", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.10", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "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": "5.16", "versionEndExcluding": "6.1.91" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.6.31" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.8.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.9" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/fa6995eeb62e74b5a1480c73fb7b420c270784d3" }, { "url": "https://git.kernel.org/stable/c/608e13706c8b6c658a0646f09ebced74ec367f7c" }, { "url": "https://git.kernel.org/stable/c/c418afb9bf23e2f2b76cb819601e4a5d9dbab42d" }, { "url": "https://git.kernel.org/stable/c/a8d89feba7e54e691ca7c4efc2a6264fa83f3687" } ], "title": "bpf: Check bloom filter map value size", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:43:50.111Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/fa6995eeb62e74b5a1480c73fb7b420c270784d3", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/608e13706c8b6c658a0646f09ebced74ec367f7c", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/c418afb9bf23e2f2b76cb819601e4a5d9dbab42d", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/a8d89feba7e54e691ca7c4efc2a6264fa83f3687", "tags": [ "x_transferred" ] } ] }, { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-36918", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-09-10T17:16:07.190878Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-09-11T17:35:00.289Z" } } ] } }