batman-adv: reject unrepresentable multicast TVLV offsets
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.
CVE-2026-80839
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-80839
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "07afe1ba288c04280622fa002ed385f1ac0b6fe6",
"lessThan": "da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2",
"versionType": "git"
},
{
"status": "affected",
"version": "07afe1ba288c04280622fa002ed385f1ac0b6fe6",
"lessThan": "916ec741e65af072b98e475feaad98c063da1b7c",
"versionType": "git"
},
{
"status": "affected",
"version": "07afe1ba288c04280622fa002ed385f1ac0b6fe6",
"lessThan": "1b466746fe109127fd983100a228cdd1f1f6ece2",
"versionType": "git"
},
{
"status": "affected",
"version": "07afe1ba288c04280622fa002ed385f1ac0b6fe6",
"lessThan": "2b46baa591d0a7c16b62f150917187e70d053be6",
"versionType": "git"
},
{
"status": "affected",
"version": "07afe1ba288c04280622fa002ed385f1ac0b6fe6",
"lessThan": "f12c2de4f542e3220e17e0606f492110064f04cb",
"versionType": "git"
}
],
"programFiles": [
"include/linux/skbuff.h",
"net/batman-adv/tvlv.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.108",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.49",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.13",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2.3",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/linux/skbuff.h",
"net/batman-adv/tvlv.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-80839
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #34855 · Revision 1
- Added to Heist Feed
- Publisher date