net/sched: cls_flower: validate mask pointer after nla_next()

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flower: validate mask pointer after nla_next() fl_set_enc_opt() iterates the key's nested tunnel-option attributes with nla_for_each_attr() while advancing a single mask pointer via nla_next() at the bottom of each loop, so the mask cursor is driven by the number of key attributes rather than by the mask's own attributes. The nla_ok() added by commit c96adff956191 ("cls_flower: call nla_ok() before nla_next()") only validates the mask pointer that was just consumed; the pointer produced by nla_next() is used by the next iteration (fl_set_geneve_opt() and siblings) without any validation. The mask's nested attributes are validated with NL_VALIDATE_LIBERAL, which merely warns on trailing bytes that do not form a complete attribute. A mask carrying one valid attribute plus 1-3 residue bytes (or a non-aligned attribute length making msk_depth negative) therefore reaches the next iteration with msk_depth != 0, so neither the !msk_depth check in fl_set_enc_opt() nor the !depth check in the per-type helpers fires. nla_type() then reads past the mask payload and nla_parse_nested_deprecated() iterates with an nla_len taken from those bytes, reading well beyond the mask attribute (KASAN: slab-out-of-bounds read in __nla_validate_parse from fl_change()). Validate the advanced mask pointer as well: when the mask is not legitimately exhausted (msk_depth != 0) and the new pointer fails nla_ok(), reject the filter with -EINVAL. An exactly exhausted mask still skips the check, preserving exact-match behaviour for the remaining key attributes.

Timeline

Scores

EPSS (exploitation in 30 days)

0.13% · top 97% of all CVEs (11 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.1.

Affected products

• Linux · Linux

  • affected 238b5ebdb6a6e4bc90810b9f8ec0063b3dfda41a – < a9283d006eef7e3b56f0f279a49bb63f6e5e61df
  • affected c96adff95619178e2118925578343ad54857c80c – < 497944d534ffb1be300365523030c7c6517cbbb6
  • affected c96adff95619178e2118925578343ad54857c80c – < a55d84907337580d91c0d54779d9d4b934633158
  • affected c96adff95619178e2118925578343ad54857c80c – < cff9bf34afde46c238189cc6f7690b7e35225df1
  • affected c96adff95619178e2118925578343ad54857c80c – < 35354bf67aa0f7bace66ffb614906124ed50d59d
  • affected c96adff95619178e2118925578343ad54857c80c – < 45e60747a9db2307929260d9aa9c1c6cbb70ee77
  • affected c96adff95619178e2118925578343ad54857c80c – < bb187146c7e5c666874784e4f3fc1bc5126e6e92
  • affected c96adff95619178e2118925578343ad54857c80c – < fee10655709c5c597e8e9f722f3035d9ea31ff3a
  • affected 5.10.11 – < 5.10.273

• Linux · Linux

  • affected 5.11
  • unaffected < 5.11
  • unaffected 5.10.273 – ≤ 5.10.*
  • unaffected 5.15.224 – ≤ 5.15.*
  • unaffected 6.1.191 – ≤ 6.1.*
  • unaffected 6.6.161 – ≤ 6.6.*
  • unaffected 6.12.115 – ≤ 6.12.*
  • unaffected 6.18.59 – ≤ 6.18.*
  • unaffected 7.2.13 – ≤ 7.2.*
  • unaffected 7.3 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-112012 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-99112](https://cveledger.app/badge/CVE-2026-99112.svg)](https://cveledger.app/cve/CVE-2026-99112)

Record last updated 31 Oct 2026, 12:43 UTC.