{"id":"CVE-2026-98622","title":"net/sched: act_ct: don't WARN on benign flow_offload_alloc() failure","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: don't WARN on benign flow_offload_alloc() failure\n\nflow_offload_alloc() returns NULL when the conntrack entry is dying\n(e.g. raced with a conntrack f…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < e8fcf3f08834e939b797311742ee72b1e2a08096","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < af475f599270e59313552e6c6f3af8507da672b8","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 424ba52c0058deeb940d02cba52eb0aeb288db33","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < d805560ad69cb266d669341ca01e26bffb0d2c67","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 00734f3684fcec42c319bedfe68a5d357c720b53","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 650787233c2fd6e515a7c5f371019a9fa080ccd2","Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 47abe7a5c4eb53269aca3506446f851572a059a3","Linux 5.7"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:42.514Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98622","references":[{"url":"https://git.kernel.org/stable/c/e8fcf3f08834e939b797311742ee72b1e2a08096"},{"url":"https://git.kernel.org/stable/c/af475f599270e59313552e6c6f3af8507da672b8"},{"url":"https://git.kernel.org/stable/c/424ba52c0058deeb940d02cba52eb0aeb288db33"},{"url":"https://git.kernel.org/stable/c/d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a"},{"url":"https://git.kernel.org/stable/c/d805560ad69cb266d669341ca01e26bffb0d2c67"},{"url":"https://git.kernel.org/stable/c/00734f3684fcec42c319bedfe68a5d357c720b53"},{"url":"https://git.kernel.org/stable/c/650787233c2fd6e515a7c5f371019a9fa080ccd2"},{"url":"https://git.kernel.org/stable/c/47abe7a5c4eb53269aca3506446f851572a059a3"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.237Z","slug":"CVE-2026-98622","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_ct: don't WARN on benign flow_offload_alloc() failure\n\nflow_offload_alloc() returns NULL when the conntrack entry is dying\n(e.g. raced with a conntrack flush) or when the GFP_ATOMIC allocation\nfails; both are expected under load and neither is a kernel bug. This\npath runs from softirq on every committed packet, so with\npanic_on_warn=1 an unprivileged user can panic the box just by racing\na conntrack flush against a `tc ... action ct commit` classifier.\n\nReproduced with a custom repro under QEMU: a small, fixed set of UDP\nflows through `tc filter ... action ct commit` on lo, raced against\nthreads flooding bare ctnetlink CT_DELETE (flush) requests. Hits\nWARNING: net/sched/act_ct.c:437 (tcf_ct_flow_table_add(), inlined\ninto tcf_ct_act() in this build) within ~15s on the unpatched kernel;\nsame setup is clean on the patched kernel. The fix itself is\nbehavior-preserving: both branches already did `goto err_alloc`\nbefore and after, only the WARN is removed.\n\n## Affected\n\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < e8fcf3f08834e939b797311742ee72b1e2a08096`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < af475f599270e59313552e6c6f3af8507da672b8`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 424ba52c0058deeb940d02cba52eb0aeb288db33`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < d805560ad69cb266d669341ca01e26bffb0d2c67`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 00734f3684fcec42c319bedfe68a5d357c720b53`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 650787233c2fd6e515a7c5f371019a9fa080ccd2`\n- `Linux >= 64ff70b80fd403110b67dd9f7184a604fdb0da43 < 47abe7a5c4eb53269aca3506446f851572a059a3`\n- `Linux 5.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}