{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2022-49961", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-06-18T10:57:27.383Z", "datePublished": "2025-06-18T11:00:22.399Z", "dateUpdated": "2025-06-18T11:00:22.399Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-06-18T11:00:22.399Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO\n\nPrecision markers need to be propagated whenever we have an ARG_CONST_*\nstyle argument, as the verifier cannot consider imprecise scalars to be\nequivalent for the purposes of states_equal check when such arguments\nrefine the return value (in this case, set mem_size for PTR_TO_MEM). The\nresultant mem_size for the R0 is derived from the constant value, and if\nthe verifier incorrectly prunes states considering them equivalent where\nsuch arguments exist (by seeing that both registers have reg->precise as\nfalse in regsafe), we can end up with invalid programs passing the\nverifier which can do access beyond what should have been the correct\nmem_size in that explored state.\n\nTo show a concrete example of the problem:\n\n0000000000000000 <prog>:\n 0: r2 = *(u32 *)(r1 + 80)\n 1: r1 = *(u32 *)(r1 + 76)\n 2: r3 = r1\n 3: r3 += 4\n 4: if r3 > r2 goto +18 <LBB5_5>\n 5: w2 = 0\n 6: *(u32 *)(r1 + 0) = r2\n 7: r1 = *(u32 *)(r1 + 0)\n 8: r2 = 1\n 9: if w1 == 0 goto +1 <LBB5_3>\n 10: r2 = -1\n\n0000000000000058 <LBB5_3>:\n 11: r1 = 0 ll\n 13: r3 = 0\n 14: call bpf_ringbuf_reserve\n 15: if r0 == 0 goto +7 <LBB5_5>\n 16: r1 = r0\n 17: r1 += 16777215\n 18: w2 = 0\n 19: *(u8 *)(r1 + 0) = r2\n 20: r1 = r0\n 21: r2 = 0\n 22: call bpf_ringbuf_submit\n\n00000000000000b8 <LBB5_5>:\n 23: w0 = 0\n 24: exit\n\nFor the first case, the single line execution's exploration will prune\nthe search at insn 14 for the branch insn 9's second leg as it will be\nverified first using r2 = -1 (UINT_MAX), while as w1 at insn 9 will\nalways be 0 so at runtime we don't get error for being greater than\nUINT_MAX/4 from bpf_ringbuf_reserve. The verifier during regsafe just\nsees reg->precise as false for both r2 registers in both states, hence\nconsiders them equal for purposes of states_equal.\n\nIf we propagated precise markers using the backtracking support, we\nwould use the precise marking to then ensure that old r2 (UINT_MAX) was\nwithin the new r2 (1) and this would never be true, so the verification\nwould rightfully fail.\n\nThe end result is that the out of bounds access at instruction 19 would\nbe permitted without this fix.\n\nNote that reg->precise is always set to true when user does not have\nCAP_BPF (or when subprog count is greater than 1 (i.e. use of any static\nor global functions)), hence this is only a problem when precision marks\nneed to be explicitly propagated (i.e. privileged users with CAP_BPF).\n\nA simplified test case has been included in the next patch to prevent\nfuture regressions."}], "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": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "2459615a8d7f44ac81f0965bc094e55ccb254717", "status": "affected", "versionType": "git"}, {"version": "457f44363a8894135c85b7a9afd2bd8196db24ab", "lessThan": "2fc31465c5373b5ca4edf2e5238558cb62902311", "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": "5.8", "status": "affected"}, {"version": "0", "lessThan": "5.8", "status": "unaffected", "versionType": "semver"}, {"version": "5.19.8", "lessThanOrEqual": "5.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.0", "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": "5.8", "versionEndExcluding": "5.19.8"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.8", "versionEndExcluding": "6.0"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2459615a8d7f44ac81f0965bc094e55ccb254717"}, {"url": "https://git.kernel.org/stable/c/2fc31465c5373b5ca4edf2e5238558cb62902311"}], "title": "bpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO\n\nPrecision markers need to be propagated whenever we have an ARG_CONST_*\nstyle argument, as the verifier cannot consider imprecise scalars to be\nequivalent for the purposes of states_equal check when such arguments\nrefine the return value (in this case, set mem_size for PTR_TO_MEM). The\nresultant mem_size for the R0 is derived from the constant value, and if\nthe verifier incorrectly prunes states considering them equivalent where\nsuch arguments exist (by seeing that both registers have reg->precise as\nfalse in regsafe), we can end up with invalid programs passing the\nverifier which can do access beyond what should have been the correct\nmem_size in that explored state.\n\nTo show a concrete example of the problem:\n\n0000000000000000 <prog>:\n 0: r2 = *(u32 *)(r1 + 80)\n 1: r1 = *(u32 *)(r1 + 76)\n 2: r3 = r1\n 3: r3 += 4\n 4: if r3 > r2 goto +18 <LBB5_5>\n 5: w2 = 0\n 6: *(u32 *)(r1 + 0) = r2\n 7: r1 = *(u32 *)(r1 + 0)\n 8: r2 = 1\n 9: if w1 == 0 goto +1 <LBB5_3>\n 10: r2 = -1\n\n0000000000000058 <LBB5_3>:\n 11: r1 = 0 ll\n 13: r3 = 0\n 14: call bpf_ringbuf_reserve\n 15: if r0 == 0 goto +7 <LBB5_5>\n 16: r1 = r0\n 17: r1 += 16777215\n 18: w2 = 0\n 19: *(u8 *)(r1 + 0) = r2\n 20: r1 = r0\n 21: r2 = 0\n 22: call bpf_ringbuf_submit\n\n00000000000000b8 <LBB5_5>:\n 23: w0 = 0\n 24: exit\n\nFor the first case, the single line execution's exploration will prune\nthe search at insn 14 for the branch insn 9's second leg as it will be\nverified first using r2 = -1 (UINT_MAX), while as w1 at insn 9 will\nalways be 0 so at runtime we don't get error for being greater than\nUINT_MAX/4 from bpf_ringbuf_reserve. The verifier during regsafe just\nsees reg->precise as false for both r2 registers in both states, hence\nconsiders them equal for purposes of states_equal.\n\nIf we propagated precise markers using the backtracking support, we\nwould use the precise marking to then ensure that old r2 (UINT_MAX) was\nwithin the new r2 (1) and this would never be true, so the verification\nwould rightfully fail.\n\nThe end result is that the out of bounds access at instruction 19 would\nbe permitted without this fix.\n\nNote that reg->precise is always set to true when user does not have\nCAP_BPF (or when subprog count is greater than 1 (i.e. use of any static\nor global functions)), hence this is only a problem when precision marks\nneed to be explicitly propagated (i.e. privileged users with CAP_BPF).\n\nA simplified test case has been included in the next patch to prevent\nfuture regressions."}], "id": "CVE-2022-49961", "lastModified": "2025-06-18T13:46:52.973", "metrics": {}, "published": "2025-06-18T11:15:23.347", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2459615a8d7f44ac81f0965bc094e55ccb254717"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2fc31465c5373b5ca4edf2e5238558cb62902311"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"affected_release": [{"advisory": "RHSA-2023:2458", "cpe": "cpe:/a:redhat:enterprise_linux:9", "package": "kernel-0:5.14.0-284.11.1.el9_2", "product_name": "Red Hat Enterprise Linux 9", "release_date": "2023-05-09T00:00:00Z"}, {"advisory": "RHSA-2023:2458", "cpe": "cpe:/o:redhat:enterprise_linux:9", "package": "kernel-0:5.14.0-284.11.1.el9_2", "product_name": "Red Hat Enterprise Linux 9", "release_date": "2023-05-09T00:00:00Z"}], "bugzilla": {"description": "kernel: bpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO", "id": "2373530", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2373530"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "verified"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nbpf: Do mark_chain_precision for ARG_CONST_ALLOC_SIZE_OR_ZERO\nPrecision markers need to be propagated whenever we have an ARG_CONST_*\nstyle argument, as the verifier cannot consider imprecise scalars to be\nequivalent for the purposes of states_equal check when such arguments\nrefine the return value (in this case, set mem_size for PTR_TO_MEM). The\nresultant mem_size for the R0 is derived from the constant value, and if\nthe verifier incorrectly prunes states considering them equivalent where\nsuch arguments exist (by seeing that both registers have reg->precise as\nfalse in regsafe), we can end up with invalid programs passing the\nverifier which can do access beyond what should have been the correct\nmem_size in that explored state.\nTo show a concrete example of the problem:\n0000000000000000 <prog>:\n0: r2 = *(u32 *)(r1 + 80)\n1: r1 = *(u32 *)(r1 + 76)\n2: r3 = r1\n3: r3 += 4\n4: if r3 > r2 goto +18 <LBB5_5>\n5: w2 = 0\n6: *(u32 *)(r1 + 0) = r2\n7: r1 = *(u32 *)(r1 + 0)\n8: r2 = 1\n9: if w1 == 0 goto +1 <LBB5_3>\n10: r2 = -1\n0000000000000058 <LBB5_3>:\n11: r1 = 0 ll\n13: r3 = 0\n14: call bpf_ringbuf_reserve\n15: if r0 == 0 goto +7 <LBB5_5>\n16: r1 = r0\n17: r1 += 16777215\n18: w2 = 0\n19: *(u8 *)(r1 + 0) = r2\n20: r1 = r0\n21: r2 = 0\n22: call bpf_ringbuf_submit\n00000000000000b8 <LBB5_5>:\n23: w0 = 0\n24: exit\nFor the first case, the single line execution's exploration will prune\nthe search at insn 14 for the branch insn 9's second leg as it will be\nverified first using r2 = -1 (UINT_MAX), while as w1 at insn 9 will\nalways be 0 so at runtime we don't get error for being greater than\nUINT_MAX/4 from bpf_ringbuf_reserve. The verifier during regsafe just\nsees reg->precise as false for both r2 registers in both states, hence\nconsiders them equal for purposes of states_equal.\nIf we propagated precise markers using the backtracking support, we\nwould use the precise marking to then ensure that old r2 (UINT_MAX) was\nwithin the new r2 (1) and this would never be true, so the verification\nwould rightfully fail.\nThe end result is that the out of bounds access at instruction 19 would\nbe permitted without this fix.\nNote that reg->precise is always set to true when user does not have\nCAP_BPF (or when subprog count is greater than 1 (i.e. use of any static\nor global functions)), hence this is only a problem when precision marks\nneed to be explicitly propagated (i.e. privileged users with CAP_BPF).\nA simplified test case has been included in the next patch to prevent\nfuture regressions."], "name": "CVE-2022-49961", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-06-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2022-49961\nhttps://nvd.nist.gov/vuln/detail/CVE-2022-49961\nhttps://lore.kernel.org/linux-cve-announce/2025061814-CVE-2022-49961-b7fa@gregkh/T"], "threat_severity": "Moderate"}