{"id":"CVE-2026-64119","summary":"l2tp: use list_del_rcu in l2tp_session_unhash","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nl2tp: use list_del_rcu in l2tp_session_unhash\n\nAn unprivileged local user can pin a host CPU indefinitely in\nl2tp_session_get_by_ifname() by issuing L2TP_CMD_SESSION_GET on\nL2TP_ATTR_IFNAME concurrently with L2TP_CMD_SESSION_CREATE and\nL2TP_CMD_SESSION_DELETE on the same tunnel. All three commands take\nGENL_UNS_ADMIN_PERM, so CAP_NET_ADMIN in the netns user namespace\nsuffices; on any host that has l2tp_core loaded the trigger is\nreachable from a standard `unshare -Urn` sandbox.\n\nl2tp_session_unhash() removes a session from tunnel-\u003esession_list\nwith list_del_init(), but that list is walked by\nl2tp_session_get_by_ifname() with list_for_each_entry_rcu() under\nrcu_read_lock_bh(). list_del_init() leaves the deleted entry's\nnext/prev self-pointing; a reader that has loaded the entry and\nthen advances pos-\u003elist.next reads &session-\u003elist, container_of()s\nback to the same session, and list_for_each_entry_rcu() never\nreaches the list head. The CPU stays in strcmp() inside the\nwalker, with BH and preemption disabled, so RCU grace periods on\nthe host stall behind it and the wedged thread cannot be killed\n(SIGKILL is delivered on syscall return).\n\nUse list_del_rcu() to match the existing list_add_rcu() in\nl2tp_session_register(); the deleted session remains visible to\nin-flight walkers with consistent next/prev pointers until\nkfree_rcu() in l2tp_session_free() releases it. tunnel-\u003esession_list\nhas exactly one list_del_init() call site; the list_del_init\n(&session-\u003eclist) at l2tp_core.c:533 operates on the per-collision\nlist, which is not walked under RCU. list_empty(&session-\u003elist) is\nnot used anywhere in net/l2tp/ after the unhash point, so dropping\nthe post-delete self-init is safe; the fix has no userspace-visible\nbehavior change.","modified":"2026-07-21T03:47:50.864004125Z","published":"2026-07-19T15:40:18.331Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64119.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5e40919a40cb3e590ed45c2a54a4a2518aa88a99"},{"type":"WEB","url":"https://git.kernel.org/stable/c/979c017803c40829b03acd9e5236e354b7622360"},{"type":"WEB","url":"https://git.kernel.org/stable/c/acab6314bb75be994f720ed13e9d9139cbf828a8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e0c3dd7b30cc5ee42ab502da140cda93d794a20b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64119.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64119"},{"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":"89b768ec2dfefaeba5212de14fc71368e12d06ba"},{"fixed":"5e40919a40cb3e590ed45c2a54a4a2518aa88a99"},{"fixed":"e0c3dd7b30cc5ee42ab502da140cda93d794a20b"},{"fixed":"acab6314bb75be994f720ed13e9d9139cbf828a8"},{"fixed":"979c017803c40829b03acd9e5236e354b7622360"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"b3dd82a879f25db9d096ae3053f657aa4260ecc6"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.11.3"},{"fixed":"6.12"}]}],"versions":["v6.11-rc1","v6.11-rc5","v6.11.2","v6.11","v6.11.1","v6.11-rc7","v6.10-rc1","v6.11-rc6","v6.11-rc3","v6.11-rc4","v6.11-rc2","v6.10","v6.10-rc6","v6.10-rc7","v6.10-rc3","v6.9-rc1","v6.10-rc5","v6.10-rc2","v6.10-rc4","v6.9","v6.9-rc6","v6.9-rc7","v6.9-rc5","v6.9-rc3","v6.9-rc2","v6.8","v6.9-rc4","v6.8-rc1","v6.7-rc1","v6.8-rc7","v6.8-rc6","v6.8-rc5","v6.8-rc4","v6.8-rc3","v6.8-rc2","v6.7","v6.7-rc3","v6.7-rc8","v6.7-rc7","v6.7-rc6","v6.7-rc2","v6.7-rc4","v6.7-rc5","v6.6","v6.6-rc1","v6.6-rc5","v6.6-rc3","v6.6-rc7","v6.6-rc6","v6.6-rc4","v6.6-rc2","v6.5","v6.5-rc1","v6.5-rc2","v6.5-rc7","v6.5-rc4","v6.5-rc3","v6.5-rc6","v6.5-rc5","v6.4","v6.4-rc7","v6.4-rc1","v6.4-rc6","v6.4-rc5","v6.4-rc3","v6.4-rc4","v6.4-rc2","v6.3","v6.3-rc1","v6.3-rc7","v6.3-rc2","v6.3-rc3","v6.3-rc5","v6.3-rc6","v6.3-rc4","v6.2-rc6","v6.2-rc1","v6.2","v6.2-rc2","v6.2-rc8","v6.2-rc5","v6.2-rc4","v6.2-rc7","v6.2-rc3","v6.1-rc1","v6.1","v6.1-rc8","v6.1-rc3","v6.1-rc6","v6.1-rc7","v6.1-rc4","v6.1-rc2","v6.1-rc5","v6.0-rc1","v6.0","v6.0-rc7","v6.0-rc3","v6.0-rc2","v6.0-rc6","v6.0-rc4","v6.0-rc5","v5.19","v5.19-rc1","v5.19-rc5","v5.19-rc8","v5.19-rc6","v5.18","v5.19-rc2","v5.19-rc7","v5.19-rc3","v5.19-rc4","v5.18-rc1","v5.18-rc7","v5.18-rc2","v5.18-rc5","v5.17","v5.18-rc4","v5.18-rc3","v5.18-rc6","v5.17-rc6","v5.17-rc4","v5.17-rc8","v5.17-rc7","v5.17-rc1","v5.17-rc3","v5.17-rc2","v5.17-rc5","v5.16","v5.16-rc1","v5.16-rc8","v5.16-rc5","v5.16-rc6","v5.16-rc7","v5.16-rc3","v5.16-rc2","v5.16-rc4","v5.15","v5.15-rc2","v5.15-rc1","v5.15-rc4","v5.15-rc7","v5.15-rc3","v5.15-rc5","v5.15-rc6","v5.14","v5.14-rc3","v5.14-rc1","v5.14-rc2","v5.14-rc7","v5.14-rc6","v5.13-rc1","v5.14-rc5","v5.14-rc4","v5.13","v5.13-rc6","v5.13-rc7","v5.13-rc3","v5.13-rc2","v5.13-rc4","v5.13-rc5","v5.12","v5.12-rc2","v5.12-rc1-dontuse","v5.12-rc1","v5.12-rc8","v5.12-rc3","v5.12-rc7","v5.12-rc5","v5.12-rc6","v5.12-rc4","v5.10","v5.11","v5.11-rc3","v5.11-rc7","v5.11-rc6","v5.11-rc5","v5.11-rc1","v5.11-rc4","v5.11-rc2","v5.10-rc1","v5.10-rc7","v5.10-rc4","v5.10-rc3","v5.10-rc6","v5.9","v5.10-rc2","v5.10-rc5","v5.9-rc1","v5.9-rc7","v5.9-rc8","v5.9-rc6","v5.9-rc4","v5.9-rc5","v5.9-rc3","v5.9-rc2","v5.8","v5.7","v5.8-rc2","v5.8-rc1","v5.8-rc7","v5.8-rc5","v5.8-rc3","v5.8-rc4","v5.8-rc6","v5.7-rc4","v5.7-rc7","v5.7-rc1","v5.7-rc3","v5.7-rc2","v5.7-rc5","v5.7-rc6","v5.6","v5.6-rc1","v5.6-rc7","v5.6-rc6","v5.6-rc3","v5.6-rc4","v5.6-rc2","v5.6-rc5","v5.5","v5.5-rc5","v5.5-rc7","v5.5-rc2","v5.5-rc1","v5.4","v5.5-rc4","v5.5-rc3","v5.5-rc6","v5.4-rc1","v5.4-rc6","v5.4-rc3","v5.4-rc4","v5.4-rc8","v5.4-rc7","v5.4-rc5","v5.3","v5.4-rc2","v5.3-rc5","v5.3-rc1","v5.3-rc2","v5.3-rc3","v5.3-rc8","v5.3-rc7","v5.3-rc4","v5.2","v5.3-rc6","v5.2-rc2","v5.2-rc7","v5.2-rc4","v5.2-rc1","v5.2-rc5","v5.2-rc6","v5.2-rc3","v5.1","v5.0-rc8","v5.1-rc7","v5.1-rc1","v5.1-rc6","v5.1-rc5","v5.0","v5.1-rc3","v5.1-rc2","v5.1-rc4","v5.0-rc1","v5.0-rc4","v5.0-rc3","v5.0-rc6","v5.0-rc7","v5.0-rc2","v5.0-rc5","v4.20-rc1","v4.19","v4.20","v4.20-rc7","v4.20-rc5","v4.20-rc6","v4.20-rc4","v4.20-rc2","v4.20-rc3","v4.19-rc2","v4.19-rc8","v4.19-rc4","v4.19-rc1","v4.19-rc7","v4.19-rc6","v4.19-rc5","v4.19-rc3","v4.18","v4.18-rc1","v4.18-rc8","v4.18-rc2","v4.18-rc5","v4.18-rc6","v4.18-rc7","v4.17","v4.18-rc3","v4.18-rc4","v4.17-rc1","v4.17-rc2","v4.17-rc7","v4.17-rc3","v4.17-rc4","v4.16","v4.17-rc6","v4.17-rc5","v4.16-rc7","v4.16-rc4","v4.16-rc1","v4.16-rc2","v4.16-rc5","v4.16-rc3","v4.16-rc6","v4.14","v4.15","v4.15-rc1","v4.15-rc4","v4.15-rc9","v4.15-rc8","v4.15-rc7","v4.15-rc3","v4.15-rc2","v4.15-rc5","v4.15-rc6","v4.14-rc1","v4.14-rc7","v4.14-rc3","v4.13","v4.14-rc8","v4.14-rc4","v4.14-rc6","v4.14-rc2","v4.14-rc5","v4.13-rc2","v4.13-rc1","v4.13-rc3","v4.13-rc7","v4.13-rc4","v4.13-rc5","v4.13-rc6","v4.12-rc1","v4.12","v4.12-rc5","v4.12-rc7","v4.12-rc6","v4.12-rc4","v4.12-rc2","v4.12-rc3","v4.11","v4.11-rc1","v4.11-rc6","v4.11-rc8","v4.11-rc7","v4.11-rc3","v4.11-rc5","v4.11-rc2","v4.11-rc4","v4.10","v4.9","v4.10-rc8","v4.10-rc3","v4.10-rc1","v4.10-rc7","v4.10-rc6","v4.10-rc2","v4.10-rc5","v4.10-rc4","v4.9-rc7","v4.9-rc6","v4.9-rc8","v4.9-rc1","v4.9-rc5","v4.9-rc3","v4.9-rc4","v4.9-rc2","v4.8","v4.8-rc8","v4.8-rc2","v4.8-rc1","v4.8-rc7","v4.8-rc6","v4.8-rc5","v4.8-rc4","v4.8-rc3","v4.7","v4.7-rc4","v4.7-rc2","v4.7-rc1","v4.7-rc7","v4.7-rc6","v4.7-rc3","v4.7-rc5","v4.6","v4.6-rc1","v4.6-rc6","v4.6-rc4","v4.6-rc7","v4.6-rc5","v4.5-rc4","v4.6-rc2","v4.6-rc3","v4.5","v4.4","v4.5-rc1","v4.5-rc6","v4.5-rc2","v4.5-rc7","v4.5-rc5","v4.5-rc3","v4.4-rc1","v4.4-rc2","v4.4-rc8","v4.4-rc3","v4.4-rc7","v4.4-rc5","v4.4-rc6","v4.4-rc4","v4.3","v4.3-rc1","v4.3-rc6","v4.3-rc4","v4.3-rc2","v4.3-rc7","v4.3-rc5","v4.3-rc3","v4.2","v4.2-rc2","v4.2-rc1","v4.2-rc8","v4.2-rc4","v4.2-rc6","v4.2-rc7","v4.0-rc5","v4.2-rc5","v4.2-rc3","v4.1-rc2","v4.1","v4.1-rc1","v4.1-rc8","v4.1-rc7","v4.1-rc6","v4.1-rc3","v4.1-rc4","v4.0","v4.1-rc5","v4.0-rc1","v4.0-rc2","v4.0-rc7","v4.0-rc3","v4.0-rc6","v4.0-rc4","v3.19","v3.19-rc7","v3.19-rc5","v3.19-rc1","v3.19-rc6","v3.19-rc4","v3.18-rc1","v3.19-rc3","v3.19-rc2","v3.18","v3.18-rc7","v3.18-rc6","v3.18-rc2","v3.18-rc3","v3.18-rc4","v3.18-rc5","v3.17","v3.17-rc1","v3.17-rc7","v3.17-rc2","v3.17-rc4","v3.16","v3.17-rc5","v3.17-rc6","v3.17-rc3","v3.16-rc7","v3.16-rc1","v3.16-rc3","v3.16-rc5","v3.16-rc6","v3.16-rc2","v3.16-rc4","v3.13","v3.15","v3.15-rc5","v3.15-rc8","v3.15-rc1","v3.15-rc6","v3.15-rc3","v3.15-rc7","v3.15-rc2","v3.15-rc4","v3.14","v3.14-rc4","v3.14-rc8","v3.14-rc7","v3.14-rc6","v3.14-rc1","v3.14-rc2","v3.14-rc5","v3.14-rc3","v3.13-rc6","v3.13-rc8","v3.12","v3.13-rc7","v3.13-rc1","v3.13-rc4","v3.13-rc3","v3.13-rc5","v3.13-rc2","v3.12-rc7","v3.12-rc3","v3.12-rc6","v3.12-rc1","v3.12-rc5","v3.11","v3.12-rc2","v3.12-rc4","v3.11-rc7","v3.11-rc2","v3.11-rc5","v3.11-rc1","v3.11-rc3","v3.11-rc4","v3.11-rc6","v3.10-rc2","v3.10","v3.10-rc7","v3.10-rc6","v3.10-rc1","v3.10-rc5","v3.10-rc3","v3.10-rc4","v3.9","v3.9-rc2","v3.9-rc7","v3.9-rc8","v3.9-rc3","v3.9-rc6","v3.9-rc5","v3.9-rc4","v3.9-rc1","v3.8","v3.8-rc7","v3.8-rc6","v3.8-rc5","v3.8-rc2","v3.8-rc1","v3.8-rc3","v3.8-rc4","v3.7","v3.7-rc1","v3.6","v3.7-rc6","v3.7-rc7","v3.7-rc3","v3.7-rc8","v3.7-rc2","v3.7-rc4","v3.7-rc5","v3.6-rc7","v3.6-rc1","v3.5-rc3","v3.6-rc6","v3.6-rc5","v3.5","v3.6-rc3","v3.6-rc4","v3.6-rc2","v3.4-rc4","v3.5-rc7","v3.5-rc5","v3.5-rc6","v3.5-rc2","v3.5-rc1","v3.5-rc4","v3.4","v3.4-rc2","v3.4-rc1","v3.4-rc7","v3.4-rc6","v3.4-rc3","v3.4-rc5","v3.3","v3.3-rc6","v3.3-rc3","v3.3-rc7","v3.3-rc2","v3.3-rc5","v3.2","v3.3-rc4","v3.3-rc1","v3.2-rc4","v3.2-rc7","v3.2-rc6","v3.2-rc5","v3.2-rc3","v3.1","v3.2-rc2","v3.2-rc1","v3.1-rc1","v3.1-rc9","v3.1-rc8","v3.1-rc10","v3.1-rc7","v3.1-rc3","v3.1-rc2","v3.1-rc4","v3.1-rc5","v3.0","v3.1-rc6","v3.0-rc7","v3.0-rc4","v3.0-rc6","v3.0-rc5","v3.0-rc3","v3.0-rc1","v2.6.39","v3.0-rc2","v2.6.38","v2.6.39-rc2","v2.6.39-rc7","v2.6.39-rc5","v2.6.39-rc1","v2.6.38-rc7","v2.6.39-rc6","v2.6.39-rc4","v2.6.39-rc3","v2.6.37","v2.6.38-rc1","v2.6.38-rc8","v2.6.38-rc2","v2.6.38-rc6","v2.6.38-rc5","v2.6.38-rc4","v2.6.38-rc3","v2.6.37-rc4","v2.6.37-rc2","v2.6.36","v2.6.37-rc5","v2.6.37-rc8","v2.6.37-rc7","v2.6.37-rc6","v2.6.37-rc1","v2.6.37-rc3","v2.6.36-rc6","v2.6.35-rc4","v2.6.36-rc8","v2.6.35","v2.6.36-rc7","v2.6.36-rc3","v2.6.36-rc5","v2.6.36-rc4","v2.6.36-rc2","v2.6.36-rc1","v2.6.35-rc5","v2.6.35-rc6","v2.6.34","v2.6.35-rc3","v2.6.35-rc1","v2.6.35-rc2","v2.6.34-rc7","v2.6.34-rc6","v2.6.34-rc5","v2.6.34-rc4","v2.6.34-rc3","v2.6.34-rc2","v2.6.34-rc1","v2.6.33","v2.6.33-rc6","v2.6.33-rc8","v2.6.33-rc4","v2.6.33-rc5","v2.6.33-rc3","v2.6.33-rc7","v2.6.33-rc2","v2.6.32","v2.6.33-rc1","v2.6.32-rc8","v2.6.32-rc7","v2.6.32-rc6","v2.6.31","v2.6.32-rc5","v2.6.32-rc4","v2.6.32-rc2","v2.6.32-rc1","v2.6.32-rc3","v2.6.31-rc9","v2.6.31-rc1","v2.6.31-rc7","v2.6.31-rc8","v2.6.31-rc6","v2.6.30-rc6","v2.6.30","v2.6.31-rc4","v2.6.31-rc5","v2.6.31-rc3","v2.6.31-rc2","v2.6.30-rc7","v2.6.30-rc8","v2.6.30-rc5","v2.6.30-rc3","v2.6.30-rc4","v2.6.30-rc1","v2.6.30-rc2","v2.6.29","v2.6.29-rc8","v2.6.29-rc7","v2.6.29-rc5","v2.6.29-rc1","v2.6.29-rc6","v2.6.29-rc4","v2.6.29-rc3","v2.6.29-rc2","v2.6.28","v2.6.28-rc7","v2.6.28-rc9","v2.6.28-rc8","v2.6.28-rc6","v2.6.28-rc5","v2.6.28-rc4","v2.6.28-rc2","v2.6.28-rc3","v2.6.28-rc1","v2.6.27","v2.6.27-rc7","v2.6.27-rc9","v2.6.27-rc8","v2.6.27-rc5","v2.6.27-rc6","v2.6.27-rc4","v2.6.27-rc1","v2.6.27-rc3","v2.6.27-rc2","v2.6.26","v2.6.26-rc9","v2.6.26-rc8","v2.6.26-rc3","v2.6.26-rc7","v2.6.26-rc6","v2.6.26-rc5","v2.6.26-rc4","v2.6.26-rc2","v2.6.26-rc1","v2.6.25","v2.6.25-rc7","v2.6.25-rc9","v2.6.25-rc8","v2.6.25-rc6","v2.6.25-rc5","v2.6.25-rc3","v2.6.25-rc4","v2.6.24","v2.6.25-rc2","v2.6.25-rc1","v2.6.24-rc8","v2.6.24-rc7","v2.6.24-rc6","v2.6.24-rc5","v2.6.24-rc4","v2.6.24-rc3","v2.6.24-rc2","v2.6.24-rc1","v2.6.23","v2.6.23-rc9","v2.6.23-rc8","v2.6.23-rc5","v2.6.23-rc7","v2.6.23-rc6","v2.6.23-rc4","v2.6.23-rc3","v2.6.23-rc2","v2.6.23-rc1","v2.6.22","v2.6.22-rc7","v2.6.22-rc6","v2.6.22-rc5","v2.6.22-rc4","v2.6.22-rc3","v2.6.22-rc2","v2.6.22-rc1","v2.6.21","v2.6.21-rc7","v2.6.21-rc6","v2.6.21-rc5","v2.6.21-rc4","v2.6.21-rc3","v2.6.21-rc2","v2.6.21-rc1","v2.6.20-rc7","v2.6.20-rc6","v2.6.20-rc5","v2.6.20-rc4","v2.6.20-rc3","v2.6.20-rc1","v2.6.20-rc2","v2.6.19-rc2","v2.6.18","v2.6.19-rc1","v2.6.18-rc6","v2.6.18-rc5","v2.6.18-rc3","v2.6.18-rc2","v2.6.18-rc1","v2.6.17","v2.6.17-rc4","v2.6.17-rc6","v2.6.17-rc5","v2.6.17-rc3","v2.6.17-rc2","v2.6.17-rc1","v2.6.16","v2.6.16-rc6","v2.6.16-rc4","v2.6.16-rc5","v2.6.16-rc3","v2.6.16-rc2","v2.6.16-rc1","v2.6.15-rc7","v2.6.15-rc5","v2.6.15-rc4","v2.6.15-rc2","v2.6.15-rc1","v2.6.14-rc3","v2.6.14-rc2","v2.6.14-rc1","v2.6.13","v2.6.13-rc7","v2.6.13-rc6","v2.6.13-rc5","v2.6.13-rc3","v2.6.13-rc4","v2.6.13-rc2","v2.6.13-rc1","v2.6.12-rc4","v2.6.12-rc3","v2.6.12-rc2"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64119.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.12.0"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64119.json"}}],"schema_version":"1.7.5"}