{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-90381", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-90381" ], "published": "2026-09-17T16:10:40Z", "summary": "wifi: mt76: fix handling channel context with different bands in mt76_switch_vif_chanctx()", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mt76: fix handling channel context with different bands in mt76_switch_vif_chanctx()\n\nWhen performing channel switches on different radios within a short\ntimeframe, channel contexts with different bands can be carried for\neach struct ieee80211_vif_chanctx_switch.\n\nRework mt76_switch_vif_chanctx() to properly handle this scenario.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v6", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v7", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": null } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-90381" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/063169a2755abdcbe7698d98360336abb6bef414" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/70869cc429fffc77de51e7777c0ecb651e8fca07" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-18T17:55:42Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 8.8, "cvss_v3_severity": "High", "scenario": "AV:A - CSA IEs in a received Beacon (ieee80211_rx_mgmt_beacon \u2192 ieee80211_sta_process_chanswitch \u2192 ieee80211_link_reserve_chanctx) or Channel Switch action frame (ieee80211_sta_rx_queued_mgmt) make ieee80211_chsw_switch_vifs call mt76_switch_vif_chanctx with one ieee80211_vif_chanctx_switch per radio; those 802.11 frames are radio-range, not a routable IP protocol.\nAC:L - ieee80211_vif_use_reserved_switch returns -EAGAIN until every in-place reservation is reserved_ready, then ieee80211_chsw_switch_vifs batches them into one CHANCTX_SWMODE_SWAP_CONTEXTS call; an AP/MLD that puts CSA IEs on two mt7996 bands with matching counts makes both ready in order with no victim-only race.\nPR:N - ieee80211_rx_mgmt_beacon only needs ieee80211_rx_our_beacon() BSSID match on an associated STA, and mt7996 sets CHANCTX_STA_CSA so this path is used; beacons are unauthenticated, so the AP or a radio-range BSSID spoof needs no Linux capability or account.\nUI:N - An already-associated station runs ieee80211_csa_switch_work \u2192 ieee80211_link_use_reserved_context when the CSA count elapses and automatically enters mt76_switch_vif_chanctx; no extra click, reconnect, or mount is required at trigger time.\nS:U - Aliased mlink->ctx, the leftover phy->chanctx on non-first radios, and any resulting host-kernel heap UAF stay inside this machine\u2019s mt76/mac80211; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The pre-fix function set every mlink->ctx to vifs[0].new_ctx. After that first ieee80211_chanctx is kfree_rcu\u2019d (ieee80211_free_chanctx when the first vif/link unassigns while others remain), mt76_vif_link_phy() still does mlink->ctx->drv_priv and reads ctx->phy from the freed object, a kernel info-leak UAF.\nI:H - The same dangling mlink->ctx makes mt76_vif_link_phy() return ctx->phy from reallocatable freed ieee80211_chanctx memory; callers such as mt7996_link_info_changed then issue MCU updates (mt7996_mcu_add_bss_info and similar) through that forged mt76_phy pointer, a kernel write/control-flow primitive.\nA:H - mt76_vif_link_phy() on the stale mlink->ctx oopses after the aliased chanctx is freed; the pre-fix path also skipped mt76_phy_update_channel for every radio but vifs[0], leaving that PHY\u2019s phy->chanctx pointing at the old ctx that ieee80211_vif_use_reserved_switch kfree_rcu\u2019s, taking the radio down." } } }