{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-90018", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-90018" ], "published": "2026-09-16T10:32:03Z", "summary": "staging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nstaging: rtl8723bs: fix OOB read / stack overflow in rtw_get_wps_attr()\n\nrtw_get_wps_attr() walks WPS attributes inside a WPS IE taken from\na wireless management frame. For each candidate attribute it only\nchecks that the fixed 4-byte attribute header (2-byte ID + 2-byte\nlength) fits inside the IE:\n\n\tif (attr_ptr + 4 > wps_ie + wps_ielen)\n\t\tbreak;\n\tu16 attr_id = get_unaligned_be16(attr_ptr);\n\tu16 attr_data_len = get_unaligned_be16(attr_ptr + 2);\n\tu16 attr_len = attr_data_len + 4;\n\nattr_data_len (and therefore attr_len) is read directly from the\nwire and is never checked against the remaining bytes in the IE\nbefore being used as the size of:\n\n\tmemcpy(buf_attr, attr_ptr, attr_len);\n\nSince attr_len is fully attacker controlled (0 to 65535+4), this is\nboth a heap OOB read of wps_ie, and, more seriously, a stack buffer\noverflow at several call sites where buf_attr is a single-byte\nstack variable, e.g. rtw_get_wps_attr_content()'s callers passing\nWPS_ATTR_SELECTED_REGISTRAR into a stack \"u8 sr\"/\"u8\nselected_registrar\" (drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c,\ndrivers/staging/rtl8723bs/core/rtw_mlme_ext.c). A crafted WPS IE in a\nbeacon or probe response processed during scanning can therefore\nsmash the stack of the parsing thread.\n\nrtw_get_wps_attr_content() itself has no independent length check\nand simply trusts the attr_len it gets back from rtw_get_wps_attr(),\nso fixing the bound here also fixes that caller.\n\nThe \"attr_ptr + 4 > wps_ie + wps_ielen\" header check above was added\nby commit 1463ca3ec6601 (\"staging: rtl8723bs: fix OOB reads in\nrtw_get_sec_ie(), rtw_get_wapi_ie(), and rtw_get_wps_attr()\"), which\nbounded the fixed header but never extended the check to cover the\nvariable-length attribute data that follows it. Add that missing\ncheck before attr_len is used as a memcpy() length or accepted as a\nmatch.", "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:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.188", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-90018" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/931640dfcb8cfa08f6cfb46229716d8072356420" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/3a6457ebf39080b87c712657fdb38f34a24fc3ff" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/fd5e24ea8373347d0352f153a66e8647337d1b10" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/a53d1ac9ce63db07943b2b2248111003851fb00f" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ff61aa3289355dafa811550a1764691cd1f5d33b" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/34f51d196c43a42046d229de5e79025d5ca553ca" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/99aa998dec83ba180822f70e6d48a514fc81c20d" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-16T14:40:32Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 8.8, "cvss_v3_severity": "High", "scenario": "AV:A - A nearby attacker injects a crafted 802.11 beacon or probe response carrying a malformed WPS IE; rtl8723bs receives it over SDIO during scan (OnBeacon/OnProbeRsp \u2192 collect_bss_info \u2192 rtw_cfg80211_inform_bss \u2192 rtw_get_wps_attr), so the attacker must be on the same WiFi radio segment.\nAC:L - The attacker fully controls the WPS attribute ID and the 16-bit length field and can reliably hit the parser on any scan; no race, rare config, or other condition outside the attacker\u2019s control is required.\nPR:N - Beacons and probe responses are processed before any association or authentication with the attacker-controlled BSS, so no local account, capability, or WiFi credentials on the victim are required.\nUI:N - Phones, Atom laptops, and IoT devices with this chip perform background and NetworkManager scans without a per-attack user action; once the interface is scanning, the driver parses received management frames on its own.\nS:U - The overflow corrupts kernel stack and adjacent heap inside the rtl8723bs driver; impact stays in the host kernel security authority and does not cross a VM, container, or IOMMU boundary.\nC:H - attr_data_len is attacker-controlled (up to 65535) and is used as a memcpy length without bounding to the IE, so the copy reads far past the WPS IE into kernel heap and the resulting stack smash can be leveraged for further disclosure.\nI:H - rtw_get_wps_attr_content() memcpy\u2019s the claimed payload into a 1-byte stack variable (u8 sr/selected_registrar) using the unchecked length, producing an attacker-sized stack overflow that can overwrite return addresses and enable kernel code execution.\nA:H - A multi-kilobyte (or wrapped near-4GB) stack smash in the scan/BSS-inform path trips stack canaries or corrupts kernel control data and causes an oops, panic, or hang of the victim device." } } }