Critical · published July 19, 2026
In the Linux kernel, the following vulnerability has been resolved:
tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()
Sashiko found that iptunnel_pmtud_build_icmp() and
iptunnel_pmtud_build_icmpv6() were caching ip_hdr() and ipv6_hdr()
before an skb_cow() call which can reallocate skb->head.
Fix this possible UAF by initializing the local variables
after the skb_cow() call.
Remove skb_reset_network_header() calls which were not needed.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 5.9, < 5.10.259 | 5.10.259 |
| linux/linux_kernel | ≥ 5.11, < 5.15.210 | 5.15.210 |
| linux/linux_kernel | ≥ 5.16, < 6.1.176 | 6.1.176 |
| linux/linux_kernel | ≥ 6.2, < 6.6.143 | 6.6.143 |
| linux/linux_kernel | ≥ 6.7, < 6.12.93 | 6.12.93 |
| linux/linux_kernel | ≥ 6.13, < 6.18.35 | 6.18.35 |
| linux/linux_kernel | ≥ 6.19, < 7.0.12 | 7.0.12 |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |
| linux/linux_kernel | all versions | — |