CVE-2026-99053 (GCVE-0-2026-99053)
Vulnerability from cvelistv5
Published
2026-10-23 12:22
Modified
2026-10-30 12:41
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
tipc: hold a reference to nodes found by link name
tipc_node_find_by_name() returns a node after dropping its RCU read lock
without taking a reference. The LINK_SET, LINK_GET and LINK_RESET_STATS
handlers then lock and access the node, racing with timer-driven cleanup of
a down peer. Generic netlink serialization does not exclude the node
timer.
The following interleaving can leave a handler using a freed node:
CPU 0: find the node under RCU and release the node read lock
CPU 1: tipc_node_timeout() clears the links and unlinks the down node
CPU 1: drop the list and timer references, queuing tipc_node_free()
CPU 0: leave the RCU read-side critical section
CPU 1: complete the grace period and free the node
CPU 0: acquire the node lock through the stale pointer
LINK_SET also uses the node's media address after releasing the node lock,
when passing queued packets to tipc_bearer_xmit().
KASAN on v7.3-rc5 reported:
BUG: KASAN: slab-use-after-free in _raw_read_lock_bh
Write of size 4 at addr ffff88807e06f008 by task poc/92
Call Trace:
_raw_read_lock_bh kernel/locking/spinlock.c:287
tipc_nl_node_set_link net/tipc/node.c:2475
genl_family_rcv_msg_doit net/netlink/genetlink.c:1114
genl_rcv_msg net/netlink/genetlink.c:1209
netlink_rcv_skb net/netlink/af_netlink.c:2575
Allocated by task 0:
tipc_node_create net/tipc/node.c:539
tipc_node_check_dest net/tipc/node.c:1196
tipc_disc_rcv net/tipc/discover.c:252
Freed by task 92:
kfree mm/slub.c:6801
rcu_core kernel/rcu/tree.c:2919
Last potentially related work creation:
__call_rcu_common.constprop.0 kernel/rcu/tree.c:3181
tipc_node_timeout net/tipc/node.c:814
Acquire a reference to the selected node with kref_get_unless_zero() before
leaving RCU, returning NULL if the node has already been released. Release
that reference on every caller exit after the last node access, including
transmission in LINK_SET. Keep the existing link lookup order and locking
so concurrent link removal still takes the existing error paths.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 Version: 6a939f365bdb03a74b4617bdb4402fc08da088b9 |
||
{
"containers": {
"cna": {
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{
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"product": "Linux",
"programFiles": [
"net/tipc/node.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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]
},
{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.19"
},
{
"lessThan": "4.19",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.273",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.224",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.191",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.113",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.57",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.11",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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"versionStartIncluding": "4.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.224",
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{
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{
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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\u0027s 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": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"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-\u003elinks[bearer_id].link into __tipc_nl_add_link(), which copies link names, properties, and statistics into the attacker\u0027s 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-\u003elock. 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."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-10-30T12:41:20.179Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/384edc67201f8561b7de952647b923f0524b1f36"
},
{
"url": "https://git.kernel.org/stable/c/5b7e58e8be90f4e8530e7a60372d003dfa7fd666"
},
{
"url": "https://git.kernel.org/stable/c/92f3b3368722631e933a4db0cf8bd578ed08cd9c"
},
{
"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"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-99053",
"datePublished": "2026-10-23T12:22:35.462Z",
"dateReserved": "2026-09-25T10:25:14.388Z",
"dateUpdated": "2026-10-30T12:41:20.179Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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