{"id":"CVE-2026-99112","state":"PUBLISHED","title":"net/sched: cls_flower: validate mask pointer after nla_next()","description":"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.","publishedAt":"2026-10-28T10:34:29.881Z","updatedAt":"2026-10-30T12:41:50.282Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a","status":"affected","lessThan":"a9283d006eef7e3b56f0f279a49bb63f6e5e61df","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"497944d534ffb1be300365523030c7c6517cbbb6","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"a55d84907337580d91c0d54779d9d4b934633158","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"cff9bf34afde46c238189cc6f7690b7e35225df1","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"35354bf67aa0f7bace66ffb614906124ed50d59d","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"45e60747a9db2307929260d9aa9c1c6cbb70ee77","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"bb187146c7e5c666874784e4f3fc1bc5126e6e92","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"fee10655709c5c597e8e9f722f3035d9ea31ff3a","versionType":"git"},{"version":"5.10.11","status":"affected","lessThan":"5.10.273","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flower.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flower.c"]}],"references":["https://git.kernel.org/stable/c/a9283d006eef7e3b56f0f279a49bb63f6e5e61df","https://git.kernel.org/stable/c/497944d534ffb1be300365523030c7c6517cbbb6","https://git.kernel.org/stable/c/a55d84907337580d91c0d54779d9d4b934633158","https://git.kernel.org/stable/c/cff9bf34afde46c238189cc6f7690b7e35225df1","https://git.kernel.org/stable/c/35354bf67aa0f7bace66ffb614906124ed50d59d","https://git.kernel.org/stable/c/45e60747a9db2307929260d9aa9c1c6cbb70ee77","https://git.kernel.org/stable/c/bb187146c7e5c666874784e4f3fc1bc5126e6e92","https://git.kernel.org/stable/c/fee10655709c5c597e8e9f722f3035d9ea31ff3a"],"weaknesses":[],"ingestedAt":"2026-10-30T13:02:04.640Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99112.json","commit":"cb14bf1b43b0c9f05f7f40eae2246263fd430780","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99112","state":"PUBLISHED","datePublished":"2026-10-28T10:34:29.881Z","dateUpdated":"2026-10-30T12:41:50.282Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.392Z"},"containers":{"cna":{"title":"net/sched: cls_flower: validate mask pointer after nla_next()","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a","status":"affected","lessThan":"a9283d006eef7e3b56f0f279a49bb63f6e5e61df","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"497944d534ffb1be300365523030c7c6517cbbb6","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"a55d84907337580d91c0d54779d9d4b934633158","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"cff9bf34afde46c238189cc6f7690b7e35225df1","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"35354bf67aa0f7bace66ffb614906124ed50d59d","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"45e60747a9db2307929260d9aa9c1c6cbb70ee77","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"bb187146c7e5c666874784e4f3fc1bc5126e6e92","versionType":"git"},{"version":"c96adff95619178e2118925578343ad54857c80c","status":"affected","lessThan":"fee10655709c5c597e8e9f722f3035d9ea31ff3a","versionType":"git"},{"version":"5.10.11","status":"affected","lessThan":"5.10.273","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flower.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.11","versionType":"semver"},{"version":"5.10.273","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.224","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.161","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.115","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.59","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.13","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/sched/cls_flower.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:41:50.282Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}