{"id":"CVE-2026-64566","published":"2026-08-05T08:16:36.140","lastModified":"2026-08-08T15:16:31.713","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()\n\nWhen iptfs_skb_add_frags() copies frag references from the source\nfrag walk into a new SKB, it increments the page reference count via\n__skb_frag_ref() but does not propagate SKBFL_SHARED_FRAG to the\ndestination SKB's skb_shinfo->flags.\n\nIf the source SKB carries shared frags (e.g. from a page-pool backed\nreceive path), the new inner SKB will appear to ESP as having privately\nowned frags.  A subsequent esp_input() call for a nested transport-mode\nSA then takes the no-COW fast path and decrypts in place, writing over\npages that are still referenced by the outer IPTFS SKB.  This causes\nkernel-visible memory corruption and can trigger a panic.\n\nAll other frag-transfer helpers in the kernel (skb_try_coalesce,\nskb_gro_receive, __pskb_copy_fclone, skb_shift, skb_segment) correctly\npropagate SKBFL_SHARED_FRAG; align iptfs_skb_add_frags() with this\nconvention by setting the flag inside the loop immediately after\n__skb_frag_ref() and nr_frags++, so every exit path that attaches a frag\nunconditionally propagates SKBFL_SHARED_FRAG.","cvssScore":9.8,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/430ea57d6daf765e88f90046afbfd1e071cb7200","tags":[]},{"url":"https://git.kernel.org/stable/c/d8aaf06b29f5a0b6186cf68d21c7d63678ee3891","tags":[]},{"url":"https://git.kernel.org/stable/c/ffd64e0717efd83fbf3396ab4e5ac6d795dac4d0","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The vulnerability in iptfs_skb_add_frags() allows for kernel memory corruption when handling shared frags, leading to potential panic conditions.","exploitability":"Exploitation requires specific conditions with shared frags and nested transport-mode SA, making it moderately difficult.","blast_radius":"If exploited, could lead to severe system instability or crashes affecting the entire system.","remediation":"Update Linux kernel to a patched version that fixes this vulnerability.","tags":["kernel","memory-corruption","frag-handling"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T06:42:54.264Z"}}