GHSA-WJ2W-7VCF-M7FJ

Vulnerability from github – Published: 2026-03-25 12:30 – Updated: 2026-06-19 15:33
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

bpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded

bond_option_mode_set() already rejects mode changes that would make a loaded XDP program incompatible via bond_xdp_check(). However, bond_option_xmit_hash_policy_set() has no such guard.

For 802.3ad and balance-xor modes, bond_xdp_check() returns false when xmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually absent due to hardware offload. This means a user can:

  1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode with a compatible xmit_hash_policy (e.g. layer2+3).
  2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded.

This leaves bond->xdp_prog set but bond_xdp_check() now returning false for the same device. When the bond is later destroyed, dev_xdp_uninstall() calls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits the bond_xdp_check() guard and returns -EOPNOTSUPP, triggering:

WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL))

Fix this by rejecting xmit_hash_policy changes to vlan+srcmac when an XDP program is loaded on a bond in 802.3ad or balance-xor mode.

commit 39a0876d595b ("net, bonding: Disallow vlan+srcmac with XDP") introduced bond_xdp_check() which returns false for 802.3ad/balance-xor modes when xmit_hash_policy is vlan+srcmac. The check was wired into bond_xdp_set() to reject XDP attachment with an incompatible policy, but the symmetric path -- preventing xmit_hash_policy from being changed to an incompatible value after XDP is already loaded -- was left unguarded in bond_option_xmit_hash_policy_set().

Note: commit 094ee6017ea0 ("bonding: check xdp prog when set bond mode") later added a similar guard to bond_option_mode_set(), but bond_option_xmit_hash_policy_set() remained unprotected.

Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-23310"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-25T11:16:27Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf/bonding: reject vlan+srcmac xmit_hash_policy change when XDP is loaded\n\nbond_option_mode_set() already rejects mode changes that would make a\nloaded XDP program incompatible via bond_xdp_check().  However,\nbond_option_xmit_hash_policy_set() has no such guard.\n\nFor 802.3ad and balance-xor modes, bond_xdp_check() returns false when\nxmit_hash_policy is vlan+srcmac, because the 802.1q payload is usually\nabsent due to hardware offload.  This means a user can:\n\n1. Attach a native XDP program to a bond in 802.3ad/balance-xor mode\n   with a compatible xmit_hash_policy (e.g. layer2+3).\n2. Change xmit_hash_policy to vlan+srcmac while XDP remains loaded.\n\nThis leaves bond-\u003exdp_prog set but bond_xdp_check() now returning false\nfor the same device.  When the bond is later destroyed, dev_xdp_uninstall()\ncalls bond_xdp_set(dev, NULL, NULL) to remove the program, which hits\nthe bond_xdp_check() guard and returns -EOPNOTSUPP, triggering:\n\nWARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL))\n\nFix this by rejecting xmit_hash_policy changes to vlan+srcmac when an\nXDP program is loaded on a bond in 802.3ad or balance-xor mode.\n\ncommit 39a0876d595b (\"net, bonding: Disallow vlan+srcmac with XDP\")\nintroduced bond_xdp_check() which returns false for 802.3ad/balance-xor\nmodes when xmit_hash_policy is vlan+srcmac.  The check was wired into\nbond_xdp_set() to reject XDP attachment with an incompatible policy, but\nthe symmetric path -- preventing xmit_hash_policy from being changed to an\nincompatible value after XDP is already loaded -- was left unguarded in\nbond_option_xmit_hash_policy_set().\n\nNote:\ncommit 094ee6017ea0 (\"bonding: check xdp prog when set bond mode\")\nlater added a similar guard to bond_option_mode_set(), but\nbond_option_xmit_hash_policy_set() remained unprotected.",
  "id": "GHSA-wj2w-7vcf-m7fj",
  "modified": "2026-06-19T15:33:07Z",
  "published": "2026-03-25T12:30:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23310"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0a80e6ecaf669c77260b44254f4a84d76bf83e89"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ace8027e41f6f094ef6c1aca42d2ed6cd7af54e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/479d589b40b836442bbdadc3fdb37f001bb67f26"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5c262bd0e39320a6d6c8277cb8349ce21c01b8c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d36ad7e126c6a0c5f699583309ccc37e3a3263ea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e85fa809e507b9d8eff4840888b8c727e4e8448c"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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