{"id":"CVE-2026-74325","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74325","summary":"wifi: mt76: use kfree_rcu for offchannel link in mt76_put_vif_phy_link","details":"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(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).","published":"2026-08-15T05:58:20.236Z","modified":"2026-08-18T03:56:46.528126393Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.40"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/50e700ac0edce72dee5c3a9755865d9423696ac7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fae097aa9a56c30febf539d72ef3773165d3aa3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c7a83899203ed36696a2d35ddd03c0f522874a63"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74325.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74325"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:46.528126393Z"}}