{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "b9022b53adad88fd6cf2b9718c9e498504f3e1dd"
            },
            {
              "fixed": "569eb11f0990849ba48706a2bfa743273707e254"
            },
            {
              "fixed": "e1dc0af719a2566ae7ccb82c0a11f70aa54908e9"
            },
            {
              "fixed": "e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.18.52"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90232.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\namt: Don't support cross-netns setup.\n\nWhen a lower device is unregistered, amt_device_event() tries\nto unregister its upper AMT device, but it has two problems.\n\n  1. amt_lookup_upper_dev() looks up an upper device in the\n      lower device's netns only\n\n  2. amt_device_event() unregisters a single upper device only\n\nIf AMT device is created on a lower device in another netns,\nremoving the lower device triggers the splat below and gets\nstuck until all upper devices are removed. [0]\n\nThe cross-netns setup seems unintentional considering 1. and\nthe following points:\n\n  * amt_link_setup() sets dev-\u003enetns_immutable to true\n  * skb_scrub_packet() is not called in the fast path\n  * iproute2 binary fails to find cross-netns lower device via\n    link-netns:\n      # ip -n ns1 link add amt0 link-netns ns2 type amt dev veth1\n      Cannot find device \"veth1\"\n\nInstead of supporting it properly and preparing for per-netns\nnetdev unreg, let's forbid cross-netns setup.\n\nNote that the problem 2. needs a separate fix.\n\n[0]:\nWARNING: net/core/dev.c:12518 at unregister_netdevice_many_notify+0x1cce/0x2250, CPU#48: ip/2031\nModules linked in:\nCPU: 48 UID: 0 PID: 2031 Comm: ip Not tainted 7.2.0-rc5+ #27 PREEMPT(full)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\nRIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:12518)\nCode: 89 ef e8 d5 52 ae fe e9 d0 f4 ff ff 48 8d 3d f9 3b 9c 02 48 c7 c6 c0 0b 63 84 ba ab 1f 00 00 67 48 0f b9 3a e9 65 ff ff ff 90 \u003c0f\u003e 0b 90 eb 81 48 8d 3d f6 3b 9c 02 48 c7 c6 c0 0b 63 84 ba e2 1f\nRSP: 0018:ffffc90004abf160 EFLAGS: 00010212\nRAX: ffff888104d38260 RBX: ffff88800b0911b8 RCX: dffffc0000000000\nRDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff85b9f880\nRBP: ffffc90004abf2d0 R08: ffffffff85b9f887 R09: 1ffffffff0b73f10\nR10: dffffc0000000000 R11: fffffbfff0b73f11 R12: ffff88800b091d08\nR13: ffff88800b091178 R14: dffffc0000000000 R15: ffff88800b091000\nFS:  00007f555b86c600(0000) GS:ffff8881942a0000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000562107d489c0 CR3: 0000000109a40002 CR4: 0000000000372ef0\nCall Trace:\n \u003cTASK\u003e\n rtnl_dellink (net/core/rtnetlink.c:3632 net/core/rtnetlink.c:3674)\n rtnetlink_rcv_msg (net/core/rtnetlink.c:7112)\n netlink_rcv_skb (net/netlink/af_netlink.c:2556)\n netlink_unicast (net/netlink/af_netlink.c:1319)\n netlink_sendmsg (net/netlink/af_netlink.c:1900)\n ____sys_sendmsg (net/socket.c:775)\n __sys_sendmsg (net/socket.c:2738)\n do_syscall_64 (arch/x86/entry/syscall_64.c:63)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121)\n...\nunregister_netdevice: waiting for veth0 to become free. Usage count = 7\nref_tracker: netdev@ffff88800d7496d8 has 3/3 users at\n     __netdev_adjacent_dev_insert (./include/linux/netdevice.h:4525 ./include/linux/netdevice.h:4554 net/core/dev.c:8791)\n     __netdev_upper_dev_link (net/core/dev.c:8879 net/core/dev.c:8963)\n     netdev_upper_dev_link (net/core/dev.c:9009)\n     amt_newlink (drivers/net/amt.c:3321)",
  "id": "CVE-2026-90232",
  "modified": "2026-09-19T03:30:50.753797886Z",
  "published": "2026-09-17T16:07:39.279Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/569eb11f0990849ba48706a2bfa743273707e254"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e1dc0af719a2566ae7ccb82c0a11f70aa54908e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90232.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90232"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "amt: Don't support cross-netns setup."
}