{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99112", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.392Z", "datePublished": "2026-10-28T10:34:29.881Z", "dateUpdated": "2026-10-31T12:43:08.195Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-31T12:43:08.195Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_flower: validate mask pointer after nla_next()\n\nfl_set_enc_opt() iterates the key's nested tunnel-option attributes\nwith nla_for_each_attr() while advancing a single mask pointer via\nnla_next() at the bottom of each loop, so the mask cursor is driven\nby the number of key attributes rather than by the mask's own\nattributes. The nla_ok() added by commit c96adff956191 (\"cls_flower:\ncall nla_ok() before nla_next()\") only validates the mask pointer\nthat was just consumed; the pointer produced by nla_next() is used by\nthe next iteration (fl_set_geneve_opt() and siblings) without any\nvalidation.\n\nThe mask's nested attributes are validated with NL_VALIDATE_LIBERAL,\nwhich merely warns on trailing bytes that do not form a complete\nattribute. A mask carrying one valid attribute plus 1-3 residue\nbytes (or a non-aligned attribute length making msk_depth negative)\ntherefore reaches the next iteration with msk_depth != 0, so neither\nthe !msk_depth check in fl_set_enc_opt() nor the !depth check in the\nper-type helpers fires. nla_type() then reads past the mask payload\nand nla_parse_nested_deprecated() iterates with an nla_len taken\nfrom those bytes, reading well beyond the mask attribute (KASAN:\nslab-out-of-bounds read in __nla_validate_parse from fl_change()).\n\nValidate the advanced mask pointer as well: when the mask is not\nlegitimately exhausted (msk_depth != 0) and the new pointer fails\nnla_ok(), reject the filter with -EINVAL. An exactly exhausted mask\nstill skips the check, preserving exact-match behaviour for the\nremaining key attributes." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "baseScore": 7.1, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - A local process supplies the malformed TCA_FLOWER_KEY_ENC_OPTS_MASK through sendmsg() on NETLINK_ROUTE; RTM_NEWTFILTER follows rtnetlink_rcv_msg() -> tc_new_tfilter() -> fl_change() -> fl_set_key() -> fl_set_enc_opt().\nAC:L - The sender controls two Geneve key attributes and a mask containing one valid attribute plus residue bytes, causing nla_next() to produce the invalid cursor deterministically without a race or external state.\nPR:L - rtnetlink_rcv_msg() requires netlink_net_capable(skb, CAP_NET_ADMIN), but checks that capability in the socket's network namespace; an unprivileged user can obtain it through a new user and network namespace.\nUI:N - The attacker can create the namespace and qdisc and submit the malformed RTM_NEWTFILTER request directly; no action by another user is required.\nS:U - The out-of-bounds access occurs in fl_set_enc_opt() within the same host kernel processing the attacker's traffic-control configuration and crosses no VM, IOMMU, or separate security authority boundary.\nC:H - A forged second Geneve mask can make fl_set_geneve_opt() copy up to 124 bytes from beyond the netlink buffer into mask->enc_opts.data, which fl_dump_key_enc_opt() can return in a filter dump.\nI:N - The faulty cursor causes out-of-bounds reads only; __nla_validate_parse() stores in-range table pointers, and the per-option helpers keep their writes within the allocated key and mask enc_opts arrays.\nA:H - The attacker-controlled fake nla_len makes __nla_validate_parse() traverse well beyond the mask allocation, as demonstrated by the KASAN slab-out-of-bounds report, and crossing inaccessible memory can cause a kernel oops." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/cls_flower.c" ], "versions": [ { "version": "238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a", "lessThan": "a9283d006eef7e3b56f0f279a49bb63f6e5e61df", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "497944d534ffb1be300365523030c7c6517cbbb6", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "a55d84907337580d91c0d54779d9d4b934633158", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "cff9bf34afde46c238189cc6f7690b7e35225df1", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "35354bf67aa0f7bace66ffb614906124ed50d59d", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "45e60747a9db2307929260d9aa9c1c6cbb70ee77", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "bb187146c7e5c666874784e4f3fc1bc5126e6e92", "status": "affected", "versionType": "git" }, { "version": "c96adff95619178e2118925578343ad54857c80c", "lessThan": "fee10655709c5c597e8e9f722f3035d9ea31ff3a", "status": "affected", "versionType": "git" }, { "version": "5.10.11", "lessThan": "5.10.273", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/cls_flower.c" ], "versions": [ { "version": "5.11", "status": "affected" }, { "version": "0", "lessThan": "5.11", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.273", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.224", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.191", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.161", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.115", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.59", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.13", "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": "5.10.11", "versionEndExcluding": "5.10.273" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "5.15.224" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.1.191" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.6.161" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.12.115" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "6.18.59" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.2.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a9283d006eef7e3b56f0f279a49bb63f6e5e61df" }, { "url": "https://git.kernel.org/stable/c/497944d534ffb1be300365523030c7c6517cbbb6" }, { "url": "https://git.kernel.org/stable/c/a55d84907337580d91c0d54779d9d4b934633158" }, { "url": "https://git.kernel.org/stable/c/cff9bf34afde46c238189cc6f7690b7e35225df1" }, { "url": "https://git.kernel.org/stable/c/35354bf67aa0f7bace66ffb614906124ed50d59d" }, { "url": "https://git.kernel.org/stable/c/45e60747a9db2307929260d9aa9c1c6cbb70ee77" }, { "url": "https://git.kernel.org/stable/c/bb187146c7e5c666874784e4f3fc1bc5126e6e92" }, { "url": "https://git.kernel.org/stable/c/fee10655709c5c597e8e9f722f3035d9ea31ff3a" } ], "title": "net/sched: cls_flower: validate mask pointer after nla_next()", "x_generator": { "engine": "bippy-1.2.0" } } } }