In the Linux kernel, the following vulnerability has been resolved: net: cap advertised IP...
🔗 CVE IDs covered (1)
📋 Description
In the Linux kernel, the following vulnerability has been resolved:
net: cap advertised IP tunnel headroom
IP tunnel devices derive their advertised needed_headroom from lower output devices. A stack of user-created devices can make the derived value larger than the 16-bit skb header offsets can represent. Once IP output reserves it, skb head expansion can wrap those offsets.
The runtime transmit path already caps a growing needed_headroom at 512. Apply the same cap when tunnel configuration publishes needed_headroom derived from a lower output device.
Capping the advertised value is safe: IP tunnel transmit still expands the skb when a packet needs more headroom. A nonsensical stacked configuration can therefore incur an extra reallocation, but it cannot publish an unbounded reservation to upper layers.
🔗 References (10)
- https://nvd.nist.gov/vuln/detail/CVE-2026-80978
- https://git.kernel.org/stable/c/6b222adeb9340306e2ff97127c76117abb9b3df8
- https://git.kernel.org/stable/c/9144f2c53a04465a6878172b523f640313c5559e
- https://git.kernel.org/stable/c/af0ee8f04bea22cdb331fa3509e17f81b48938ad
- https://git.kernel.org/stable/c/bc4e05ae66c9797a0972ac44326e69c5305e0020
- https://git.kernel.org/stable/c/84783961cb8bdb36b4f41a02ce43aafc6d52b176
- https://git.kernel.org/stable/c/b160422f8103574425e2834130e169d84c94fa1d
- https://git.kernel.org/stable/c/d36e75f5669140b66515ad3a176ca6337bd80a5e
- https://git.kernel.org/stable/c/fb889a619723032140f5d983a3a34d25a5a2bed4
- https://github.com/advisories/GHSA-p2qp-rm9g-w8f3