{"id":"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   \u003cIRQ\u003e\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().","modified":"2026-09-18T03:48:32.458142602Z","published":"2026-09-16T08:48:25.689Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89789.json","cna_assigner":"Linux"},"references":[{"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"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"459aa660eb1d8ce67080da1983bb81d716aa5a69"},{"fixed":"fcafb2b1430824bae4258c01a439ec97ca0c6973"},{"fixed":"3ca3da5c305caa873ddb81e8c6b118143f6dd3d1"},{"fixed":"6f815c2fb6ab20385f81c353cdad0ea3b88132af"},{"fixed":"e3b9aa0773abd5d4ed90be41ce5306c146d5b09e"},{"fixed":"fd8396cfecbd904468c71362f08aaa25f96d5337"},{"fixed":"7677eb2cbf2cc7446de474c01a6b06277c0051e5"},{"fixed":"8d85498016a5bb56339734a14c276209fa65bafc"},{"fixed":"d989e22ae9802c52c56ad4284d0caf26696cf6ae"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89789.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.7.0"},{"fixed":"5.10.270"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.221"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.188"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.157"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.110"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.52"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89789.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}