{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-50164", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-10-21T19:36:19.962Z", "datePublished": "2024-11-07T09:31:41.012Z", "dateUpdated": "2026-08-05T11:42:12.665Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:42:12.665Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix overloading of MEM_UNINIT's meaning\n\nLonial reported an issue in the BPF verifier where check_mem_size_reg()\nhas the following code:\n\n if (!tnum_is_const(reg->var_off))\n /* For unprivileged variable accesses, disable raw\n * mode so that the program is required to\n * initialize all the memory that the helper could\n * just partially fill up.\n */\n meta = NULL;\n\nThis means that writes are not checked when the register containing the\nsize of the passed buffer has not a fixed size. Through this bug, a BPF\nprogram can write to a map which is marked as read-only, for example,\n.rodata global maps.\n\nThe problem is that MEM_UNINIT's initial meaning that \"the passed buffer\nto the BPF helper does not need to be initialized\" which was added back\nin commit 435faee1aae9 (\"bpf, verifier: add ARG_PTR_TO_RAW_STACK type\")\ngot overloaded over time with \"the passed buffer is being written to\".\n\nThe problem however is that checks such as the above which were added later\nvia 06c1c049721a (\"bpf: allow helpers access to variable memory\") set meta\nto NULL in order force the user to always initialize the passed buffer to\nthe helper. Due to the current double meaning of MEM_UNINIT, this bypasses\nverifier write checks to the memory (not boundary checks though) and only\nassumes the latter memory is read instead.\n\nFix this by reverting MEM_UNINIT back to its original meaning, and having\nMEM_WRITE as an annotation to BPF helpers in order to then trigger the\nBPF verifier checks for writing to memory.\n\nSome notes: check_arg_pair_ok() ensures that for ARG_CONST_SIZE{,_OR_ZERO}\nwe can access fn->arg_type[arg - 1] since it must contain a preceding\nARG_PTR_TO_MEM. For check_mem_reg() the meta argument can be removed\naltogether since we do check both BPF_READ and BPF_WRITE. Same for the\nequivalent check_kfunc_mem_size_reg()." } ], "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 vulnerability is reached through the bpf(2) syscall (BPF_MAP_CREATE/BPF_MAP_FREEZE/BPF_PROG_LOAD) by a process on the local system. Per kernel scoring guidance, BPF verifier bugs are Local.\nAC:L - The attacker fully authors the BPF program and the map contents; passing a non-constant size register to a helper such as bpf_skb_load_bytes() deterministically bypasses the write check every time. No race, timing window, or uncontrolled memory layout is involved.\nPR:L - An unprivileged local user can load a BPF_PROG_TYPE_SOCKET_FILTER program reaching bpf_skb_load_bytes() when kernel.unprivileged_bpf_disabled=0 (default on kernels without CONFIG_BPF_UNPRIV_DEFAULT_OFF, e.g. Android and many embedded builds), and CAP_BPF is delegable into unprivileged user namespaces via BPF tokens (bpf_token_capable() uses ns_capable). No real root in the init namespace is needed.\nUI:N - The attacker performs every step itself — creating and freezing the map, loading the program, and triggering it (e.g. by sending a packet to its own socket). No other user's action is required.\nS:U - The verifier bypass and its impact are both within the kernel's own security authority; this is a standard local privilege escalation with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - Writing to a frozen BPF_F_RDONLY_PROG map desynchronizes the values the verifier constant-folded via bpf_map_direct_read()/__mark_reg_known() from the values used at runtime, so bounds the verifier proved safe become arbitrarily out-of-bounds, yielding an arbitrary kernel memory read primitive.\nI:H - The bug directly permits a BPF program to write into memory the verifier guarantees is immutable (.rodata global maps, PTR_TO_MAP_KEY, read-only PTR_TO_MEM/PTR_TO_BUF, and program context), and the resulting verifier invariant break escalates to an arbitrary kernel write and full privilege escalation.\nA:H - Out-of-bounds kernel reads and writes resulting from the broken verifier bounds reasoning readily corrupt kernel memory and panic the system, and the attacker can trigger this repeatedly." } ] } ], "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": "97e6d7dab1ca4648821c790a2b7913d6d5d549db", "lessThan": "43f4df339a4d375bedcad29a61ae6f0ee7a048f8", "status": "affected", "versionType": "git" }, { "version": "97e6d7dab1ca4648821c790a2b7913d6d5d549db", "lessThan": "48068ccaea957469f1adf78dfd2c1c9a7e18f0fe", "status": "affected", "versionType": "git" }, { "version": "97e6d7dab1ca4648821c790a2b7913d6d5d549db", "lessThan": "54bc31682660810af1bed7ca7a19f182df8d3df8", "status": "affected", "versionType": "git" }, { "version": "97e6d7dab1ca4648821c790a2b7913d6d5d549db", "lessThan": "8ea607330a39184f51737c6ae706db7fdca7628e", "status": "affected", "versionType": "git" }, { "version": "6099a6c8a749a5c8d5f8b4c4342022a92072a02b", "status": "affected", "versionType": "git" }, { "version": "bfe25df63048edd4ceaf78a2fc755d5e2befc978", "status": "affected", "versionType": "git" }, { "version": "717c39718dbc4f7ebcbb7b625fb11851cd9007fe", "status": "affected", "versionType": "git" }, { "version": "5d0bba8232bf22ce13747cbfc8f696318ff01a50", "status": "affected", "versionType": "git" }, { "version": "70674d11d14eeecad90be4b409a22b902112ba32", "status": "affected", "versionType": "git" }, { "version": "a08d942ecbf46e23a192093f6983cb1d779f4fa8", "status": "affected", "versionType": "git" }, { "version": "5.15.45", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "5.17.13", "lessThan": "5.18", "status": "affected", "versionType": "semver" }, { "version": "5.18.2", "lessThan": "5.19", "status": "affected", "versionType": "semver" } ] }, { "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": "5.19", "status": "affected" }, { "version": "0", "lessThan": "5.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.125", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.59", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.6", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "5.19", "versionEndExcluding": "6.1.125" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.6.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.11.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.19", "versionEndExcluding": "6.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.45" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.17.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/43f4df339a4d375bedcad29a61ae6f0ee7a048f8" }, { "url": "https://git.kernel.org/stable/c/48068ccaea957469f1adf78dfd2c1c9a7e18f0fe" }, { "url": "https://git.kernel.org/stable/c/54bc31682660810af1bed7ca7a19f182df8d3df8" }, { "url": "https://git.kernel.org/stable/c/8ea607330a39184f51737c6ae706db7fdca7628e" } ], "title": "bpf: Fix overloading of MEM_UNINIT's meaning", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T20:43:57.432Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:38:18.068Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }