{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74325","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-15T05:44:03.884Z","datePublished":"2026-08-15T05:58:20.236Z","dateUpdated":"2026-08-17T05:45:54.629Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T05:45:54.629Z"},"descriptions":[{"lang":"en","value":"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)."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local nl80211/genl paths (NL80211_CMD_REMAIN_ON_CHANNEL, CANCEL_REMAIN_ON_CHANNEL, TRIGGER_SCAN) that call mt76_put_vif_phy_link during ROC/scan teardown; remote WiFi frames cannot invoke this free path.\nAC:L - Exploitation is a race between ROC/scan completion freeing the offchannel mlink and the TX datapath still dereferencing it under RCU; an attacker with nl80211 access controls both sides by starting offchannel ops, queuing offchannel TX, and cancelling ROC concurrently.\nPR:L - Entry points require GENL_UNS_ADMIN_PERM (CAP_NET_ADMIN in the socket user namespace). Per CNA guidance this is Low because unprivileged users can obtain CAP_NET_ADMIN via user namespaces and drive ROC/scan on an mt76 multi-radio interface they control.\nUI:N - No victim interaction is required once the attacker can issue nl80211 ROC/scan commands and offchannel TX; exploitation does not depend on a user opening files, mounting filesystems, or clicking prompts.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the same OS security boundary; it does not cross VM, container, or IOMMU isolation boundaries on its own.\nC:H - This is a use-after-free of struct mt76_vif_link freed via kfree while TX paths such as mt7996_mac_write_txwi still rcu_dereference and read mlink fields; UAF enables heap grooming for arbitrary kernel memory disclosure.\nI:H - Freed mlink contents control TXWI fields (omac_idx, wmm_idx, band_idx, bss idx) passed to firmware DMA descriptors; UAF provides a practical path to corrupt kernel heap metadata and achieve arbitrary code execution.\nA:H - Dereferencing the freed offchannel_link in the TX worker/softirq path causes kernel oops or panic; UAF on a hot transmit path can crash multi-radio mt76 APs, routers, and client devices during P2P/scan offchannel operations."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/channel.c"],"versions":[{"version":"a8f424c1287cc79a06c21816658feea87dfcb83f","lessThan":"c7a83899203ed36696a2d35ddd03c0f522874a63","status":"affected","versionType":"git"},{"version":"a8f424c1287cc79a06c21816658feea87dfcb83f","lessThan":"50e700ac0edce72dee5c3a9755865d9423696ac7","status":"affected","versionType":"git"},{"version":"a8f424c1287cc79a06c21816658feea87dfcb83f","lessThan":"7fae097aa9a56c30febf539d72ef3773165d3aa3","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/wireless/mediatek/mt76/channel.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.18.40","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.5","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2"}]}]}],"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"}],"title":"wifi: mt76: use kfree_rcu for offchannel link in mt76_put_vif_phy_link","x_generator":{"engine":"bippy-1.2.0"}}}}