{"id":"CVE-2026-64577","published":"2026-08-05T08:16:37.630","lastModified":"2026-08-08T15:16:32.670","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: check skb_pull_data() return in gtp1u_send_echo_resp()\n\ngtp1u_send_echo_resp() ignores skb_pull_data()'s return value. Its\ncaller gtp1u_udp_encap_recv() only guarantees 16 bytes (udphdr +\ngtp1_header), but the pull requests 20 (gtp1_header_long + udphdr). For\na 16-19 byte echo request the pull fails and returns NULL without\nadvancing skb->data; execution continues, and the following skb_push()\nplus the IP header pushed by iptunnel_xmit() move skb->data below\nskb->head, tripping skb_under_panic().\n\nFix it by dropping the packet when skb_pull_data() fails.\n\n  skbuff: skb_under_panic: ...\n  kernel BUG at net/core/skbuff.c:214!\n  Call Trace:\n   skb_push (net/core/skbuff.c:2648)\n   iptunnel_xmit (net/ipv4/ip_tunnel_core.c:82)\n   gtp_encap_recv (drivers/net/gtp.c:701 drivers/net/gtp.c:808 drivers/net/gtp.c:920)\n   udp_queue_rcv_one_skb (net/ipv4/udp.c:2388)\n   ...\n  Kernel panic - not syncing: Fatal exception in interrupt","cvssScore":7.5,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/4fc7923871d176ce0e5fecf4a9b7bb915af790ed","tags":[]},{"url":"https://git.kernel.org/stable/c/961e9b1e33445f8e42859ecc020c9f60d8b69a8b","tags":[]},{"url":"https://git.kernel.org/stable/c/b3c733eaae7f362601c28ac1533d47a961cd3e1c","tags":[]},{"url":"https://git.kernel.org/stable/c/cd170f051dba9ac146fabcd1b91726487c0cb9fa","tags":[]},{"url":"https://git.kernel.org/stable/c/cf45d748e437b8dd2dd987f27ee79c8c86f95c88","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"This vulnerability in the Linux kernel's GTP (Generic Tunneling Protocol) implementation allows a malicious packet with specific payload to cause a kernel panic by triggering an invalid memory access.","exploitability":"Exploitation requires crafting a specially crafted GTP echo request packet that fails skb_pull_data(), making it moderately difficult but feasible for attackers with network control over the interface.","blast_radius":"If exploited, this could lead to a denial of service (DoS) condition on affected systems, potentially causing kernel crashes and system instability.","remediation":"Update the Linux kernel to the patched version as soon as possible to mitigate this vulnerability.","tags":["dos","kernel","gtp"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T06:58:35.734Z"}}