FKIE_CVE-2026-90232

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-17 17:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: amt: Don't support cross-netns setup. When a lower device is unregistered, amt_device_event() tries to unregister its upper AMT device, but it has two problems. 1. amt_lookup_upper_dev() looks up an upper device in the lower device's netns only 2. amt_device_event() unregisters a single upper device only If AMT device is created on a lower device in another netns, removing the lower device triggers the splat below and gets stuck until all upper devices are removed. [0] The cross-netns setup seems unintentional considering 1. and the following points: * amt_link_setup() sets dev->netns_immutable to true * skb_scrub_packet() is not called in the fast path * iproute2 binary fails to find cross-netns lower device via link-netns: # ip -n ns1 link add amt0 link-netns ns2 type amt dev veth1 Cannot find device "veth1" Instead of supporting it properly and preparing for per-netns netdev unreg, let's forbid cross-netns setup. Note that the problem 2. needs a separate fix. [0]: WARNING: net/core/dev.c:12518 at unregister_netdevice_many_notify+0x1cce/0x2250, CPU#48: ip/2031 Modules linked in: CPU: 48 UID: 0 PID: 2031 Comm: ip Not tainted 7.2.0-rc5+ #27 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 RIP: 0010:unregister_netdevice_many_notify (net/core/dev.c:12518) Code: 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 RSP: 0018:ffffc90004abf160 EFLAGS: 00010212 RAX: ffff888104d38260 RBX: ffff88800b0911b8 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff85b9f880 RBP: ffffc90004abf2d0 R08: ffffffff85b9f887 R09: 1ffffffff0b73f10 R10: dffffc0000000000 R11: fffffbfff0b73f11 R12: ffff88800b091d08 R13: ffff88800b091178 R14: dffffc0000000000 R15: ffff88800b091000 FS: 00007f555b86c600(0000) GS:ffff8881942a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562107d489c0 CR3: 0000000109a40002 CR4: 0000000000372ef0 Call Trace: <TASK> rtnl_dellink (net/core/rtnetlink.c:3632 net/core/rtnetlink.c:3674) rtnetlink_rcv_msg (net/core/rtnetlink.c:7112) netlink_rcv_skb (net/netlink/af_netlink.c:2556) netlink_unicast (net/netlink/af_netlink.c:1319) netlink_sendmsg (net/netlink/af_netlink.c:1900) ____sys_sendmsg (net/socket.c:775) __sys_sendmsg (net/socket.c:2738) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) ... unregister_netdevice: waiting for veth0 to become free. Usage count = 7 ref_tracker: netdev@ffff88800d7496d8 has 3/3 users at __netdev_adjacent_dev_insert (./include/linux/netdevice.h:4525 ./include/linux/netdevice.h:4554 net/core/dev.c:8791) __netdev_upper_dev_link (net/core/dev.c:8879 net/core/dev.c:8963) netdev_upper_dev_link (net/core/dev.c:9009) amt_newlink (drivers/net/amt.c:3321)
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/569eb11f0990849ba48706a2bfa743273707e254
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e1dc0af719a2566ae7ccb82c0a11f70aa54908e9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/amt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "569eb11f0990849ba48706a2bfa743273707e254",
              "status": "affected",
              "version": "b9022b53adad88fd6cf2b9718c9e498504f3e1dd",
              "versionType": "git"
            },
            {
              "lessThan": "e1dc0af719a2566ae7ccb82c0a11f70aa54908e9",
              "status": "affected",
              "version": "b9022b53adad88fd6cf2b9718c9e498504f3e1dd",
              "versionType": "git"
            },
            {
              "lessThan": "e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06",
              "status": "affected",
              "version": "b9022b53adad88fd6cf2b9718c9e498504f3e1dd",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/amt.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\namt: Don\u0027t 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\u0027s 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\u0027s 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",
  "lastModified": "2026-09-17T17:17:19.043",
  "metrics": {},
  "published": "2026-09-17T17:17:19.043",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/569eb11f0990849ba48706a2bfa743273707e254"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e1dc0af719a2566ae7ccb82c0a11f70aa54908e9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e99ecc3046ea5f5c6b5e1f8b4ef854c6c6998e06"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.