{"id":"CVE-2026-89789","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-89789","summary":"gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free\n\ngtp_newlink()'s error path frees tid_hash and addr_hash without\nwaiting for an RCU grace period after clearing sk_user_data. A\nconcurrent gtp_encap_recv() in softirq may still hold the gtp_dev\npointer obtained via rcu_dereference_sk_user_data() and access the\nfreed memory.\n\n  BUG: KASAN: slab-use-after-free in gtp0_pdp_find+0x1f6/0x200 (gtp.c:152)\n  Call Trace:\n   <IRQ>\n   gtp0_pdp_find+0x1f6/0x200\n   gtp_encap_recv+0x527/0x24b0\n   udp_queue_rcv_one_skb+0x75f/0xc10\n\nAdd synchronize_net() before the kfree calls in out_hashtable, which\ncovers all error paths from both gtp_encap_enable() and\ngtp_create_sockets().","published":"2026-09-16T08:48:25.689Z","modified":"2026-09-17T03:47:22.466656993Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"5.10.270"}],"fix":null,"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/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6f815c2fb6ab20385f81c353cdad0ea3b88132af"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7677eb2cbf2cc7446de474c01a6b06277c0051e5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8d85498016a5bb56339734a14c276209fa65bafc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d989e22ae9802c52c56ad4284d0caf26696cf6ae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fcafb2b1430824bae4258c01a439ec97ca0c6973"},{"type":"WEB","url":"https://git.kernel.org/stable/c/fd8396cfecbd904468c71362f08aaa25f96d5337"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89789.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89789"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-17T03:47:22.466656993Z"}}