{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98027", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:19:56.070Z", "datePublished": "2026-09-25T10:23:45.123Z", "dateUpdated": "2026-10-19T09:12:32.331Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:12:32.331Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size\n\nmv88e6xxx_get_rxnfc() uses rxnfc->rule_cnt as the write index while\ndumping the policy IDR, clobbering the input value before it has been\nlooked at. That input is the number of entries the caller had room for.\nETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the\nbuffer from the rule_cnt userspace passes in, so once an admin has\ninstalled policy rules any user can ask for fewer slots than there are\nrules and run off the end of the allocation. A rule_cnt of 0 leaves the\nbuffer pointer NULL and the walk dereferences it.\n\nCount into a local so the caller's limit survives the walk, and stop with\n-EMSGSIZE once it is reached." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow is reached only through the local SIOCETHTOOL ioctl: dev_ethtool() -> ethtool_get_rxnfc() -> dsa_user_get_rxnfc() -> mv88e6xxx_get_rxnfc(ETHTOOL_GRXCLSRLALL). The bad input is the rule_cnt field of the ethtool_rxnfc struct the user passes in. No network packet reaches this path.\nAC:H - The OOB write only happens if policy rules already exist in chip->policies for that DSA port. Those are installed by an admin via ETHTOOL_SRXCLSRLINS, which needs CAP_NET_ADMIN over the hardware port. The attacker can't create that state. Once rules exist, a small rule_cnt triggers it deterministically.\nPR:L - dev_ethtool() lists ETHTOOL_GRXCLSRLALL among the commands exempt from the ns_capable(CAP_NET_ADMIN) check. Any unprivileged local user who can see the mv88e6xxx user port in their netns can issue the ioctl.\nUI:N - The attacker makes the ioctl call and picks rule_cnt themselves. No other user has to do anything.\nS:U - The corruption hits the kernel heap in the same kernel that runs the attacker's ioctl. No VM, IOMMU or other authority boundary is crossed.\nC:H - ethtool_get_rxnfc() sizes rule_buf with kcalloc(rule_cnt, 4) from the user's value. The driver then overwrites rxnfc->rule_cnt with the real rule count, so ethtool_rxnfc_copy_to_user() copies that many u32s from the undersized buffer, reading past the slab object into userspace. The same heap corruption can also be groomed to leak more.\nI:H - mv88e6xxx_get_rxnfc() writes rule_locs[rxnfc->rule_cnt++] = id for every rule on the port with no bound, so u32 IDs go past a kmalloc object whose size and cache the attacker chose via rule_cnt. That heap OOB write can corrupt neighbouring objects.\nA:H - With rule_cnt=0, ethtool_get_rxnfc() passes a NULL rule_buf and the IDR walk writes through it, oopsing the kernel on demand. Larger overflows corrupt slab memory and can panic the system. Either can be repeated." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/dsa/mv88e6xxx/chip.c" ], "versions": [ { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "7e4bfc5f0b66feb22cba821303fc25ca22cd0887", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "01124cd2cf4b71755b1130ac82d78dcfbd5d69e3", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "609c4378f212cf580aae02250f1146caf63d873f", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "c5b5c52b6524c9fb50def2260baac745c095ec3a", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "44cd4674d9aa5bdf793b8a8b481c9e8536ed6070", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "7a683c2b062810bca203e41866389daf387c235b", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "cda5ac8fe8ac8e80b1703ebb8c4250726fc19739", "status": "affected", "versionType": "git" }, { "version": "da7dc87553046a43be1620a783ce3d9f6583d322", "lessThan": "b1fffc273112e7284c5b705e186b43b5770cd3d5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/dsa/mv88e6xxx/chip.c" ], "versions": [ { "version": "5.4", "status": "affected" }, { "version": "0", "lessThan": "5.4", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.7", "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": "5.4", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "7.2.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7e4bfc5f0b66feb22cba821303fc25ca22cd0887" }, { "url": "https://git.kernel.org/stable/c/01124cd2cf4b71755b1130ac82d78dcfbd5d69e3" }, { "url": "https://git.kernel.org/stable/c/609c4378f212cf580aae02250f1146caf63d873f" }, { "url": "https://git.kernel.org/stable/c/c5b5c52b6524c9fb50def2260baac745c095ec3a" }, { "url": "https://git.kernel.org/stable/c/44cd4674d9aa5bdf793b8a8b481c9e8536ed6070" }, { "url": "https://git.kernel.org/stable/c/7a683c2b062810bca203e41866389daf387c235b" }, { "url": "https://git.kernel.org/stable/c/cda5ac8fe8ac8e80b1703ebb8c4250726fc19739" }, { "url": "https://git.kernel.org/stable/c/b1fffc273112e7284c5b705e186b43b5770cd3d5" } ], "title": "net: dsa: mv88e6xxx: bound the policy rule dump by the caller's buffer size", "x_generator": { "engine": "bippy-1.2.0" } } } }