{"id":"CVE-2026-99053","summary":"tipc: hold a reference to nodes found by link name","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ntipc: hold a reference to nodes found by link name\n\ntipc_node_find_by_name() returns a node after dropping its RCU read lock\nwithout taking a reference.  The LINK_SET, LINK_GET and LINK_RESET_STATS\nhandlers then lock and access the node, racing with timer-driven cleanup of\na down peer.  Generic netlink serialization does not exclude the node\ntimer.\n\nThe following interleaving can leave a handler using a freed node:\n\n  CPU 0: find the node under RCU and release the node read lock\n  CPU 1: tipc_node_timeout() clears the links and unlinks the down node\n  CPU 1: drop the list and timer references, queuing tipc_node_free()\n  CPU 0: leave the RCU read-side critical section\n  CPU 1: complete the grace period and free the node\n  CPU 0: acquire the node lock through the stale pointer\n\nLINK_SET also uses the node's media address after releasing the node lock,\nwhen passing queued packets to tipc_bearer_xmit().\n\nKASAN on v7.3-rc5 reported:\n\n  BUG: KASAN: slab-use-after-free in _raw_read_lock_bh\n  Write of size 4 at addr ffff88807e06f008 by task poc/92\n  Call Trace:\n   _raw_read_lock_bh                 kernel/locking/spinlock.c:287\n   tipc_nl_node_set_link             net/tipc/node.c:2475\n   genl_family_rcv_msg_doit          net/netlink/genetlink.c:1114\n   genl_rcv_msg                      net/netlink/genetlink.c:1209\n   netlink_rcv_skb                   net/netlink/af_netlink.c:2575\n\n  Allocated by task 0:\n   tipc_node_create                  net/tipc/node.c:539\n   tipc_node_check_dest              net/tipc/node.c:1196\n   tipc_disc_rcv                     net/tipc/discover.c:252\n\n  Freed by task 92:\n   kfree                             mm/slub.c:6801\n   rcu_core                          kernel/rcu/tree.c:2919\n\n  Last potentially related work creation:\n   __call_rcu_common.constprop.0     kernel/rcu/tree.c:3181\n   tipc_node_timeout                 net/tipc/node.c:814\n\nAcquire a reference to the selected node with kref_get_unless_zero() before\nleaving RCU, returning NULL if the node has already been released.  Release\nthat reference on every caller exit after the last node access, including\ntransmission in LINK_SET.  Keep the existing link lookup order and locking\nso concurrent link removal still takes the existing error paths.","modified":"2026-11-01T02:32:28.935188329Z","published":"2026-10-23T12:22:35.462Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99053.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1428c5f1d346a2e1ac9156713975a72246957009"},{"type":"WEB","url":"https://git.kernel.org/stable/c/17e73bae400f6a434dc006e3bee92c94cf781954"},{"type":"WEB","url":"https://git.kernel.org/stable/c/384edc67201f8561b7de952647b923f0524b1f36"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3c3b308ee6e25729a6cf09b69cdd0e093220d40b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5b7e58e8be90f4e8530e7a60372d003dfa7fd666"},{"type":"WEB","url":"https://git.kernel.org/stable/c/92f3b3368722631e933a4db0cf8bd578ed08cd9c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b60259d4047fbb735476c729dcf9306a038b6110"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f17e70206a1e763fcca2578a8db3c4eed0f843a9"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/99xxx/CVE-2026-99053.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99053"},{"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":"6a939f365bdb03a74b4617bdb4402fc08da088b9"},{"fixed":"384edc67201f8561b7de952647b923f0524b1f36"},{"fixed":"5b7e58e8be90f4e8530e7a60372d003dfa7fd666"},{"fixed":"92f3b3368722631e933a4db0cf8bd578ed08cd9c"},{"fixed":"b60259d4047fbb735476c729dcf9306a038b6110"},{"fixed":"f17e70206a1e763fcca2578a8db3c4eed0f843a9"},{"fixed":"1428c5f1d346a2e1ac9156713975a72246957009"},{"fixed":"3c3b308ee6e25729a6cf09b69cdd0e093220d40b"},{"fixed":"17e73bae400f6a434dc006e3bee92c94cf781954"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99053.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.19.0"},{"fixed":"5.10.273"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.224"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.191"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.160"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.113"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.57"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-99053.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}