{"id":"CVE-2026-23310","title":"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 inc…","summary":"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 inc…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.15, < 6.6.130","linux_kernel >= 6.7, < 6.12.77","linux_kernel >= 6.13, < 6.18.17","linux_kernel >= 6.19, < 6.19.7","linux_kernel = 7.0"],"patched":["linux_kernel 6.19.7"],"published":"2026-03-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:18:48.810","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-23310","references":[{"url":"https://git.kernel.org/stable/c/0a80e6ecaf669c77260b44254f4a84d76bf83e89","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/0ace8027e41f6f094ef6c1aca42d2ed6cd7af54e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/479d589b40b836442bbdadc3fdb37f001bb67f26","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5c262bd0e39320a6d6c8277cb8349ce21c01b8c1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d36ad7e126c6a0c5f699583309ccc37e3a3263ea","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e85fa809e507b9d8eff4840888b8c727e4e8448c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00123,"epssPercentile":0.01844,"ingestedAt":"2026-10-15T03:30:12.841Z","slug":"CVE-2026-23310","body":"## Overview\n\nIn 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->xdp_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.\n\n## Affected\n\n- `linux_kernel >= 5.15, < 6.6.130`\n- `linux_kernel >= 6.7, < 6.12.77`\n- `linux_kernel >= 6.13, < 6.18.17`\n- `linux_kernel >= 6.19, < 6.19.7`\n- `linux_kernel = 7.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.19.7`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}