CVE-2026-99053

Full vulnerability record from the local CVENow database.

Description

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.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-23 13:17:28.877000

Last modified

2026-10-30 13:21:41.943000

View original CVE JSON

{
  "id": "CVE-2026-99053",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:28.877",
  "lastModified": "2026-10-30T13:21:41.943",
  "vulnStatus": "Received",
  "cveTags": [],
  "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."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/tipc/node.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
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              "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9",
              "lessThan": "384edc67201f8561b7de952647b923f0524b1f36",
              "versionType": "git",
              "status": "affected"
            },
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              "lessThan": "5b7e58e8be90f4e8530e7a60372d003dfa7fd666",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9",
              "lessThan": "92f3b3368722631e933a4db0cf8bd578ed08cd9c",
              "versionType": "git",
              "status": "affected"
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              "versionType": "git",
              "status": "affected"
            },
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              "lessThan": "f17e70206a1e763fcca2578a8db3c4eed0f843a9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9",
              "lessThan": "1428c5f1d346a2e1ac9156713975a72246957009",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6a939f365bdb03a74b4617bdb4402fc08da088b9",
              "lessThan": "3c3b308ee6e25729a6cf09b69cdd0e093220d40b",
              "versionType": "git",
              "status": "affected"
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              "versionType": "git",
              "status": "affected"
            }
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        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
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          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.19",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.19",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.273",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.224",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.113",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "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",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1428c5f1d346a2e1ac9156713975a72246957009",
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}