batman-adv: reject unrepresentable multicast TVLV offsets
Summary
| CVE | CVE-2026-80839 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-04 16:18:12 UTC |
| Updated | 2026-09-04 16:18:12 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: batman-adv: reject unrepresentable multicast TVLV offsets The network and transport header fields in struct sk_buff are 16-bit offsets from skb->head, and U16_MAX is reserved as the unset transport header value. batadv_tvlv_call_handler() sets both fields from a received multicast TVLV without checking whether the TVLV end is representable. If the end offset exceeds the field's range, skb_set_transport_header() truncates it so that the transport header precedes the network header. The negative difference is then returned by skb_network_header_len() as a large u32. batadv_mcast_forw_packet() consequently accepts an oversized multicast tracker and accesses memory beyond the skb data. Add skb_set_transport_header_careful(), an offset-aware counterpart to skb_reset_transport_header_careful(), which validates the final head-relative offset before assigning it. Use the new helper in batadv_tvlv_call_handler() and reject unrepresentable TVLVs before setting the network header. |
Risk And Classification
EPSS: 0.001680000 probability, percentile 0.063400000 (date 2026-09-07)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 07afe1ba288c04280622fa002ed385f1ac0b6fe6 da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2 git | Not specified |
| CNA | Linux | Linux | affected 07afe1ba288c04280622fa002ed385f1ac0b6fe6 916ec741e65af072b98e475feaad98c063da1b7c git | Not specified |
| CNA | Linux | Linux | affected 07afe1ba288c04280622fa002ed385f1ac0b6fe6 1b466746fe109127fd983100a228cdd1f1f6ece2 git | Not specified |
| CNA | Linux | Linux | affected 07afe1ba288c04280622fa002ed385f1ac0b6fe6 2b46baa591d0a7c16b62f150917187e70d053be6 git | Not specified |
| CNA | Linux | Linux | affected 07afe1ba288c04280622fa002ed385f1ac0b6fe6 f12c2de4f542e3220e17e0606f492110064f04cb git | Not specified |
| CNA | Linux | Linux | affected 6.8 | Not specified |
| CNA | Linux | Linux | unaffected 6.8 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.108 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.49 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.13 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.3 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/f12c2de4f542e3220e17e0606f492110064f04cb | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/2b46baa591d0a7c16b62f150917187e70d053be6 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/1b466746fe109127fd983100a228cdd1f1f6ece2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/916ec741e65af072b98e475feaad98c063da1b7c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.