CVE-2026-81000
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
net: tun: bound receive headroom
In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tun_get_user() uses tun->align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is larger than the usable space in a one-page skb head, SKB_MAX_HEAD(align) underflows and the result becomes negative when stored in good_linear. That value later wraps when assigned to the size_t linear variable, and tun_alloc_skb() can place skb->data outside the allocated head. Bound the headroom stored by TUN to the one-page skb-head budget and the largest non-sentinel 16-bit skb header offset. Leave one linear byte for raw TUN and a complete Ethernet header for TAP, including NET_IP_ALIGN. Also pull the raw-TUN protocol byte and the TAP Ethernet header before accessing them, so these checks remain safe for nonlinear skbs supplied by other allocation paths.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | ad715e713610d2d5473c3a6498c825ccecf26491 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 708e87937de93f445225c134a2e20519f9b4ce60 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 18ef24cdb2eba32e38f1d27f2d02b7b4212e8f76 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 010eee265d6bd8769b6a523d2a0693d9b3f5df43 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 379d85c7f25f3e05a428225e6b8a65613c6e9b9d | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | e098d9cc8859614a7f7baebc96e32a5a16b18ed2 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 0ada54ea63e48b9c1608e917ccb7dfadbe86db28 | Unavailable | None listed |
| eaea34b23c46bf17b4a5638be69ab3561854f34b | affected | git | 447c9303942c439a117d9b76ce6d6e2116b38ee7 | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 4.6 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 4.6 | Unavailable | None listed |
| 5.10.270 | unaffected | semver | Unavailable | 5.10.* | None listed |
| 5.15.221 | unaffected | semver | Unavailable | 5.15.* | None listed |
| 6.1.188 | unaffected | semver | Unavailable | 6.1.* | None listed |
| 6.6.157 | unaffected | semver | Unavailable | 6.6.* | None listed |
| 6.12.109 | unaffected | semver | Unavailable | 6.12.* | None listed |
| 6.18.50 | unaffected | semver | Unavailable | 6.18.* | None listed |
| 7.2.4 | unaffected | semver | Unavailable | 7.2.* | None listed |
| 7.3 | unaffected | original_commit_for_fix | Unavailable | * | None listed |