CVE-2026-98369

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm: add missing rcu_read_lock(), skb_dst_force() and dev_hold() for xfrm_trans_reinject() syzbot reported a suspicious RCU usage warning in ip6_pkt_drop(): WARNING: suspicious RCU usage in ip6_pkt_drop include/net/addrconf.h:389 suspicious rcu_dereference_check() usage! Call Trace: __in6_dev_get_safely include/net/addrconf.h:389 [inline] ip6_pkt_drop+0x596/0x610 net/ipv6/route.c:4620 ip6_pkt_discard+0x1c/0x30 net/ipv6/route.c:4651 xfrm_trans_reinject+0x324/0x630 net/xfrm/xfrm_input.c:806 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 When commit 4f4920669d21 ("xfrm: Reinject transport-mode packets through workqueue") converted xfrm_trans_reinject from a tasklet to a workqueue, the reinjection loop ceased running in softirq context. Workqueue workers run in process context where local_bh_disable() does not enter an RCU read-side critical section under CONFIG_PREEMPT_RCU. Because finish callbacks (such as ip6_rcv_finish) expect to run under an RCU read lock (performing route lookups, l3mdev lookups, and accessing RCU-protected data structures), invoking them in workqueue context without rcu_read_lock() triggers RCU lockdep warnings. Furthermore, packets queued to the workqueue via xfrm_trans_queue_net() may carry non-refcounted (noref) dst entries (e.g. from ip_route_input_noref). Additionally, on netdevice unregistration, dst_dev_put() replaces dst->dev with blackhole_netdev, so dst entries do not keep skb->dev alive while queued in the workqueue. Fix these issues by: 1. Calling skb_dst_force(skb) in xfrm_trans_queue_net() while still in the caller's RCU section to ensure dst is reference-counted before queuing. 2. Holding a reference on skb->dev via dev_hold()/dev_put() across workqueue deferral so skb->dev remains valid during finish() callback processing. 3. Acquiring rcu_read_lock() around the finish callback invocation loop in xfrm_trans_reinject().

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

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

Published

2026-10-06 09:18:31.280000

Last modified

2026-10-19 10:18:40.010000

View original CVE JSON

{
  "id": "CVE-2026-98369",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:18:31.280",
  "lastModified": "2026-10-19T10:18:40.010",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: add missing rcu_read_lock(), skb_dst_force() and dev_hold() for xfrm_trans_reinject()\n\nsyzbot reported a suspicious RCU usage warning in ip6_pkt_drop():\n\n  WARNING: suspicious RCU usage in ip6_pkt_drop\n  include/net/addrconf.h:389 suspicious rcu_dereference_check() usage!\n\n  Call Trace:\n   __in6_dev_get_safely include/net/addrconf.h:389 [inline]\n   ip6_pkt_drop+0x596/0x610 net/ipv6/route.c:4620\n   ip6_pkt_discard+0x1c/0x30 net/ipv6/route.c:4651\n   xfrm_trans_reinject+0x324/0x630 net/xfrm/xfrm_input.c:806\n   process_one_work kernel/workqueue.c:3322 [inline]\n   process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n   worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486\n\nWhen commit 4f4920669d21 (\"xfrm: Reinject transport-mode packets through\nworkqueue\") converted xfrm_trans_reinject from a tasklet to a workqueue,\nthe reinjection loop ceased running in softirq context. Workqueue workers\nrun in process context where local_bh_disable() does not enter an RCU\nread-side critical section under CONFIG_PREEMPT_RCU.\n\nBecause finish callbacks (such as ip6_rcv_finish) expect to run under an\nRCU read lock (performing route lookups, l3mdev lookups, and accessing\nRCU-protected data structures), invoking them in workqueue context without\nrcu_read_lock() triggers RCU lockdep warnings.\n\nFurthermore, packets queued to the workqueue via xfrm_trans_queue_net()\nmay carry non-refcounted (noref) dst entries (e.g. from ip_route_input_noref).\nAdditionally, on netdevice unregistration, dst_dev_put() replaces dst->dev\nwith blackhole_netdev, so dst entries do not keep skb->dev alive while\nqueued in the workqueue.\n\nFix these issues by:\n1. Calling skb_dst_force(skb) in xfrm_trans_queue_net() while still in the\n   caller's RCU section to ensure dst is reference-counted before queuing.\n2. Holding a reference on skb->dev via dev_hold()/dev_put() across workqueue\n   deferral so skb->dev remains valid during finish() callback processing.\n3. Acquiring rcu_read_lock() around the finish callback invocation loop in\n   xfrm_trans_reinject()."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/xfrm/xfrm_input.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7d98b26684cb2390729525b341ea099f0badbe18",
              "lessThan": "41e47f1664be86c91326f0afe0504a1162d00907",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "6601d91a85761f33351c71e04ec0bbd294ca07ce",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "0cda8273265d30cac6423834fd7d4acb75f04fdb",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "68a317b4aec8ca1868a39d69e40f9e29baa4f40a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "6eb3b071be8e260543c604550c54dac66e6b174b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "664fc0941df7c1918b2cd4de6ee00469ba77d8e4",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4f4920669d21e1060b7243e5118dc3b71ced1276",
              "lessThan": "d2f5082f9e84653fa1a9e8aebaaff23e688f5e19",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "f520075da484306bbb8425afd2c42404ba74816f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "130d9e5017ade1b81d16783563edb38c12a2eab7",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5.15.75",
              "lessThan": "5.15.222",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "5.19.17",
              "lessThan": "5.20",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "6.0.3",
              "lessThan": "6.1",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/xfrm/xfrm_input.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.1",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.222",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.189",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.54",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "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/0cda8273265d30cac6423834fd7d4acb75f04fdb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/41e47f1664be86c91326f0afe0504a1162d00907",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6601d91a85761f33351c71e04ec0bbd294ca07ce",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/664fc0941df7c1918b2cd4de6ee00469ba77d8e4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/68a317b4aec8ca1868a39d69e40f9e29baa4f40a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6eb3b071be8e260543c604550c54dac66e6b174b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d2f5082f9e84653fa1a9e8aebaaff23e688f5e19",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}