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CVE PROGRAM SOURCE RECORD7.8 High

CVE-2026-98442

net/sched: act_ct: fix helper UAF due to extensions realloc

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • a21b06e7319129994f339ed47f512bbe57b77f5b to < 31f5fe29a572037ee19c233dfe506849940c484baffected
  • a21b06e7319129994f339ed47f512bbe57b77f5b to < 1679bbf5fbeac52a310b1a58b2b301bbf388bdbfaffected
  • a21b06e7319129994f339ed47f512bbe57b77f5b to < 812c16a255e7773a544e88b39ae6daed25544d30affected
  • a21b06e7319129994f339ed47f512bbe57b77f5b to < 8988f4d11f3fba0ab38122178836c683ad516a05affected
  • a21b06e7319129994f339ed47f512bbe57b77f5b to < dad19b59da050cb60d3f7023dac2a042a84bf0bdaffected

Linux Linux

Default version status: affected

  • 6.2affected
  • 0 to < 6.2unaffected
  • 6.6.160 to ≤ 6.6.*unaffected
  • 6.12.112 to ≤ 6.12.*unaffected
  • 6.18.55 to ≤ 6.18.*unaffected
  • 7.2.9 to ≤ 7.2.*unaffected
  • 7.3 to ≤ *unaffected

References