CVE-2026-80838 (GCVE-0-2026-80838)

Vulnerability from cvelistv5 – Published: 2026-09-04 15:54 – Updated: 2026-10-19 08:44
VLAI
Title
vxlan: keep the last remote linked during FDB flush
Summary
In the Linux kernel, the following vulnerability has been resolved: vxlan: keep the last remote linked during FDB flush A non-nexthop FDB entry is expected to have at least one remote while it remains reachable through the FDB hash table. A filtered bulk flush violates this invariant when every remote matches: It unlinks the last remote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush() to destroy the parent FDB entry. An RCU reader can find the parent during this interval. first_remote_rcu() then applies list_entry_rcu() to the empty list head, producing an invalid remote pointer that the receive learning path can read from and write to. When a matching remote is the sole remaining remote, leave it linked and ask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps the remote attached while sending the deletion notification and removing the parent from the lookup structures.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6641 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 2a7c2f00843225d5f037676bca649321f3d024c7 (git)
Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < a8820c8a7718327e96849782033e7c85a0f6bcfe (git)
Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c (git)
Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < 4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab (git)
Affected: c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f , < d5d4a7b538b52db63927773a8905fcd9f78a42e2 (git)
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Linux Linux Affected: 6.7
Unaffected: 0 , < 6.7 (semver)
Unaffected: 6.12.108 , ≤ 6.12.* (semver)
Unaffected: 6.18.49 , ≤ 6.18.* (semver)
Unaffected: 7.1.13 , ≤ 7.1.* (semver)
Unaffected: 7.2.3 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
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{
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          "programFiles": [
            "drivers/net/vxlan/vxlan_core.c"
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    "datePublished": "2026-09-04T15:54:48.371Z",
    "dateReserved": "2026-08-26T14:34:25.796Z",
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      "cve": "CVE-2026-80838",
      "id": "CVE-2026-80838",
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      "product_status:known_affected": "1",
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      "source": "Red Hat CSAF VEX",
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      "title": "kernel: vxlan: keep the last remote linked during FDB flush",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80838.json",
      "version": "3"
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}



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