{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-90232",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-90232"
  ],
  "published": "2026-09-17T16:10:40Z",
  "summary": "amt: Don't support cross-netns setup.",
  "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->netns_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 <0f> 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 <TASK>\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)",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-90232"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/569eb11f0990849ba48706a2bfa743273707e254"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e1dc0af719a2566ae7ccb82c0a11f70aa54908e9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-17T16:10:40Z"
  }
}