{"id":"CVE-2026-99112","title":"net/sched: cls_flower: validate mask pointer after nla_next()","summary":"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 advanc…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a < a9283d006eef7e3b56f0f279a49bb63f6e5e61df","Linux >= c96adff95619178e2118925578343ad54857c80c < 497944d534ffb1be300365523030c7c6517cbbb6","Linux >= c96adff95619178e2118925578343ad54857c80c < a55d84907337580d91c0d54779d9d4b934633158","Linux >= c96adff95619178e2118925578343ad54857c80c < cff9bf34afde46c238189cc6f7690b7e35225df1","Linux >= c96adff95619178e2118925578343ad54857c80c < 35354bf67aa0f7bace66ffb614906124ed50d59d","Linux >= c96adff95619178e2118925578343ad54857c80c < 45e60747a9db2307929260d9aa9c1c6cbb70ee77","Linux >= c96adff95619178e2118925578343ad54857c80c < bb187146c7e5c666874784e4f3fc1bc5126e6e92","Linux >= c96adff95619178e2118925578343ad54857c80c < fee10655709c5c597e8e9f722f3035d9ea31ff3a","Linux >= 5.10.11 < 5.10.273","Linux 5.11"],"published":"2026-10-28","updated":"2026-10-31","sourceUpdated":"2026-10-31T12:43:08.195Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99112","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"}],"tags":["cve.org"],"epss":0.00132,"epssPercentile":0.02769,"ingestedAt":"2026-10-28T11:09:40.453Z","slug":"CVE-2026-99112","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a < a9283d006eef7e3b56f0f279a49bb63f6e5e61df`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < 497944d534ffb1be300365523030c7c6517cbbb6`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < a55d84907337580d91c0d54779d9d4b934633158`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < cff9bf34afde46c238189cc6f7690b7e35225df1`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < 35354bf67aa0f7bace66ffb614906124ed50d59d`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < 45e60747a9db2307929260d9aa9c1c6cbb70ee77`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < bb187146c7e5c666874784e4f3fc1bc5126e6e92`\n- `Linux >= c96adff95619178e2118925578343ad54857c80c < fee10655709c5c597e8e9f722f3035d9ea31ff3a`\n- `Linux >= 5.10.11 < 5.10.273`\n- `Linux 5.11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":233306,"id":"CVE-2026-99112","ts":1793896011817,"field":"cvss","old":null,"new":"7.1"},{"seq":233305,"id":"CVE-2026-99112","ts":1793896011817,"field":"severity","old":"none","new":"high"}]}