CVE-2026-93805

wifi: cfg80211: validate rx/tx MLME callback frame lengths before access

cve-program · severity unknownCVSS unknownCheck source for fixed versionsKEV status unknown

Original advisory

Historical advisory recorded 23 Oct 2026 15:48:27 UTC. Read the latest advisory.

cve-program · CVE-2026-93805

Published

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: validate rx/tx MLME callback frame lengths before access cfg80211_rx_mlme_mgmt() and cfg80211_tx_mlme_mgmt() call tracepoints before rejecting frames shorter than the frame-control field. After that, they only require len >= 2 before dispatching into subtype handlers that assume their fixed fields are present. The frames that trip this are not shorter than 2 bytes; they are short relative to their subtype. mwifiex is a concrete in-tree example on the length side: mwifiex_process_mgmt_packet() only requires a 4-address ieee80211_hdr plus the 2-byte firmware length prefix before handing the frame to cfg80211_rx_mlme_mgmt(). After stripping the length prefix and removing addr4, pkt_len can be exactly 24: a bare 3-address management header with no reason-code body. The existing WARN_ON(len < 2) does not fire on such a frame, and cfg80211_process_deauth() then reads u.deauth.reason_code as a two-byte access starting at offset 24, immediately past the 24-byte buffer. Add a frame-control length gate, then validate each subtype's minimum frame size in an if/else-if chain that mirrors the dispatch logic. Trace only after the frame is known to be well-formed. Side effects of this change: - The WARN_ON(len < 2) is dropped. It only guarded the frame_control read, never the subtype fixed fields, and it does not fire on the frames that actually trigger the out-of-bounds read (which are >= 2). The len >= 2 check is kept as the guard before dereferencing frame_control, but without the warning: these are exported callbacks and a malformed frame from a driver should be dropped silently rather than backtraced. - cfg80211_tx_mlme_mgmt() previously routed every non-deauth subtype through disassociation handling; it now silently ignores unrecognised subtypes.

Read the publisher's advisory

Affected versions, risk and source history

cve-program · CVE-2026-93805

Published

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/wireless/mlme.c"
                    ],
                    "versions": [
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "6eb4bd50be53f5afbabb3a3b5153276e08fa7a4a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "ce2a3be6909462f49c34de96be71f0ad5f0d573f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "6bdf4dcff98df634e04ebf99f52027a48d7f78ff",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "0ec738a0d361d7eb37188117166d201f9df622d3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "8f4127a93cf60d561ad39849a9ac763ba0e14db5",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "6829c878ecd24ff0ae41b4668c7e9d0f11b66942",
                            "lessThan": "d5e4586546974179feca305a94e07fac3e9727fe",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                }

Linux

Vendor product

Publisher's version information

Shown as published. These rules are not interpreted as NuGet package version ranges.

{
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/wireless/mlme.c"
                    ],
                    "versions": [
                        {
                            "version": "2.6.32",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "2.6.32",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.222",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.189",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.158",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.111",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.53",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }

Original source record · Cite this exact observation · Complete original publisher JSON