{"id":"CVE-2026-74325","title":"wifi: mt76: use kfree_rcu for offchannel link in mt76_put_vif_phy_link","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: use kfree_rcu for offchannel link in mt76_put_vif_phy_link\n\nmt76_put_vif_phy_link() frees the offchannel mlink with plain kfree()\nafter rcu_assign_pointer(N…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < c7a83899203ed36696a2d35ddd03c0f522874a63","Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < 50e700ac0edce72dee5c3a9755865d9423696ac7","Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < 7fae097aa9a56c30febf539d72ef3773165d3aa3","Linux 6.14"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:53:28.772438Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T18:55:33.235Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74325","references":[{"url":"https://git.kernel.org/stable/c/c7a83899203ed36696a2d35ddd03c0f522874a63"},{"url":"https://git.kernel.org/stable/c/50e700ac0edce72dee5c3a9755865d9423696ac7"},{"url":"https://git.kernel.org/stable/c/7fae097aa9a56c30febf539d72ef3773165d3aa3"}],"tags":["cve.org"],"epss":0.00173,"epssPercentile":0.06317,"ingestedAt":"2026-10-16T19:46:24.378Z","slug":"CVE-2026-74325","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: use kfree_rcu for offchannel link in mt76_put_vif_phy_link\n\nmt76_put_vif_phy_link() frees the offchannel mlink with plain kfree()\nafter rcu_assign_pointer(NULL). However, rcu_assign_pointer only prevents\nfuture RCU readers from obtaining the pointer -- it does not wait for\nexisting readers that already hold it via rcu_dereference.\n\nThe TX datapath (e.g. mt7996_mac_write_txwi) dereferences mlink->wcid\nand mlink->idx under rcu_read_lock. If a TX softirq obtained the pointer\nvia rcu_dereference just before the NULL assignment, it will dereference\nfreed memory after the kfree.\n\nstruct mt76_vif_link already contains an rcu_head field that is unused at\nthis free site -- a developer oversight, since the adjacent\nkfree_rcu_mightsleep call for rx_sc in the same function shows the\npattern was understood.\n\nReplace kfree(mlink) with kfree_rcu(mlink, rcu_head).\n\n## Affected\n\n- `Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < c7a83899203ed36696a2d35ddd03c0f522874a63`\n- `Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < 50e700ac0edce72dee5c3a9755865d9423696ac7`\n- `Linux >= a8f424c1287cc79a06c21816658feea87dfcb83f < 7fae097aa9a56c30febf539d72ef3773165d3aa3`\n- `Linux 6.14`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}