{"id":"CVE-2026-64577","summary":"gtp: check skb_pull_data() return in gtp1u_send_echo_resp()","details":"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-\u003edata; execution continues, and the following skb_push()\nplus the IP header pushed by iptunnel_xmit() move skb-\u003edata below\nskb-\u003ehead, 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","modified":"2026-08-06T03:48:34.427622774Z","published":"2026-08-05T08:09:33.135Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64577.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4fc7923871d176ce0e5fecf4a9b7bb915af790ed"},{"type":"WEB","url":"https://git.kernel.org/stable/c/961e9b1e33445f8e42859ecc020c9f60d8b69a8b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b3c733eaae7f362601c28ac1533d47a961cd3e1c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cd170f051dba9ac146fabcd1b91726487c0cb9fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cf45d748e437b8dd2dd987f27ee79c8c86f95c88"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64577.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64577"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9af41cc33471ea1efa6f77e188f055cc77d0a5c5"},{"fixed":"b3c733eaae7f362601c28ac1533d47a961cd3e1c"},{"fixed":"4fc7923871d176ce0e5fecf4a9b7bb915af790ed"},{"fixed":"961e9b1e33445f8e42859ecc020c9f60d8b69a8b"},{"fixed":"cf45d748e437b8dd2dd987f27ee79c8c86f95c88"},{"fixed":"cd170f051dba9ac146fabcd1b91726487c0cb9fa"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64577.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.18.0"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64577.json"}}],"schema_version":"1.8.0"}