{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-99053", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.388Z", "datePublished": "2026-10-23T12:22:35.462Z", "dateUpdated": "2026-10-24T14:10:13.569Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-24T14:10:13.569Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The attacker-controlled selector is TIPC_NLA_LINK_NAME in a local NETLINK_GENERIC TIPC_NL_LINK_GET request, dispatched to tipc_nl_node_get_link() and patched tipc_node_find_by_name(). Remote packets can create or down the peer but cannot invoke this handler, so one remote actor cannot trigger the UAF.\nAC:L - The same local attacker can create TIPC peers in user/network namespaces, stop one so node_lost_contact() sets delete_at, and flood LINK_GET while tipc_node_timeout() performs cleanup. Both sides of this repeatable race are attacker-controlled, and the submitted PoC reached the KASAN UAF.\nPR:L - TIPC_NL_LINK_GET is registered without an administrative permission flag and reaches tipc_nl_node_get_link() for any local netlink caller. Setup mutators use GENL_UNS_ADMIN_PERM and the family has netnsok=true, allowing an unprivileged user to obtain the necessary namespace-local rights.\nUI:N - The attacker can create and stop its own TIPC peer and issue the racing TIPC_NL_LINK_GET requests without any victim action.\nS:U - The stale pointer from tipc_node_find_by_name() corrupts host-kernel tipc_node and tipc_link slab objects; no VM, IOMMU, or other security-authority boundary is crossed.\nC:H - TIPC_NL_LINK_GET follows a reclaimed node->links[bearer_id].link into __tipc_nl_add_link(), which copies link names, properties, and statistics into the attacker's netlink reply. Heap grooming can therefore turn the stale node into an arbitrary kernel-read primitive.\nI:H - _raw_read_lock_bh() already performs the reported four-byte write to freed node->lock. With a reclaimed links pointer, TIPC_NL_LINK_RESET_STATS reaches tipc_link_reset_stats(), whose memset() provides an attacker-directed kernel write suitable for further corruption or control-flow hijacking.\nA:H - The observed slab use-after-free occurs while tipc_nl_node_set_link() locks the freed node; corrupted lock state or the subsequent stale node/link dereferences can cause a kernel oops or panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/tipc/node.c" ], "versions": [ { "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9", "lessThan": "b60259d4047fbb735476c729dcf9306a038b6110", "status": "affected", "versionType": "git" }, { "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9", "lessThan": "f17e70206a1e763fcca2578a8db3c4eed0f843a9", "status": "affected", "versionType": "git" }, { "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9", "lessThan": "1428c5f1d346a2e1ac9156713975a72246957009", "status": "affected", "versionType": "git" }, { "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9", "lessThan": "3c3b308ee6e25729a6cf09b69cdd0e093220d40b", "status": "affected", "versionType": "git" }, { "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9", "lessThan": "17e73bae400f6a434dc006e3bee92c94cf781954", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/tipc/node.c" ], "versions": [ { "version": "4.19", "status": "affected" }, { "version": "0", "lessThan": "4.19", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.160", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.57", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.11", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.6.160" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.12.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.18.57" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "7.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b60259d4047fbb735476c729dcf9306a038b6110" }, { "url": "https://git.kernel.org/stable/c/f17e70206a1e763fcca2578a8db3c4eed0f843a9" }, { "url": "https://git.kernel.org/stable/c/1428c5f1d346a2e1ac9156713975a72246957009" }, { "url": "https://git.kernel.org/stable/c/3c3b308ee6e25729a6cf09b69cdd0e093220d40b" }, { "url": "https://git.kernel.org/stable/c/17e73bae400f6a434dc006e3bee92c94cf781954" } ], "title": "tipc: hold a reference to nodes found by link name", "x_generator": { "engine": "bippy-1.2.0" } } } }