From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f51.google.com (mail-wm1-f51.google.com [209.85.128.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 27E6A49251A for ; Tue, 5 May 2026 17:38:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778002709; cv=none; b=kIjYxKOeVdibAA/cEzNxRhNkd6lTaYjyDXKqNVhBkz0wQ99e8UmhcHXUCKtSyhuo092GQCbk76K6vT5dq/nDJ7BQS8PirMxEHnD0EINT14eejcXIN+fVOTu5K1qHmL/iAn0nkQJi+O1AEFLKVQioGY8tt3OjbW4s4ElvzWqy7hE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778002709; c=relaxed/simple; bh=8CBrQmbEsdNgHXYKb6wsIXwlaQPjAq3SREKqrhhl4GQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Z5+1mW50gjpVSb1nnMpJWjTL1yQaVVXuD8aTbDVrymKM7yvQ/6+ovvjYfMU9gQQtuyIuNSwKU6FlEUOdfaf5NJdaZ45duz4kliEZZTrZqYkfB+k4a7qtOgcWZBlRDHDTnDl3xGEmL8nPNIoO/toXGoRei2i9qxlNJQMtXemv7d0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=imh0GeTP; arc=none smtp.client-ip=209.85.128.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="imh0GeTP" Received: by mail-wm1-f51.google.com with SMTP id 5b1f17b1804b1-48a563e4ef7so53529485e9.0 for ; Tue, 05 May 2026 10:38:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778002707; x=1778607507; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=+NEFajvV+WD5zm8pAD2atBhqQcX592r+fg8eqdbXZVU=; b=imh0GeTPqwgiXldXRicNcUnTeIofIHrGGDSMe+ZXspdqdKhjHCRP0n1pJG9mOzXr5K F3SEW0WBzm/rfBMJT94Evi19hZMzoqrZp+WAcKKPpqGX6rdNe0H4wDjE7nXqhyQ6eTLI o5HsGQb+zBZyLfE9iHLi30kuSAx0I5sn2C+eCfxRIiSSu5B9qaHmH7pjL8AFFecwj0Hp t6JZC8kawpWEcYK5hugawHLVAt/81DnK765afH3sdgYfzrdBf7rWBfHaKJLAqZYdx7yj IBEbpK/vOvxx0qhk+7hWj8r9XuaJB1buSNE4dRccDw7GSpnk1CqBY6xhE95aRbtVm4SV /NDg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778002707; x=1778607507; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=+NEFajvV+WD5zm8pAD2atBhqQcX592r+fg8eqdbXZVU=; b=qCy0DlMoNUbUt4pcbKbpMJII9q+cyPgXJJ6Md27Ty7BTMHiOcinleY0gH5KBqRF1/7 I4U2lDLUTA8MieXdWm9Kcf/cai2wsm0IaBEsliX3rW1E37DOWf9ZYIdYy5mrS8Qj1hNA ejtnGEVg4mKl1JDW6BerFUgxilfaHvfz8UmlDo6031INpworYpxwvwSmNLm5ugrrCJKR ZZykPZIdi2kIbkG7qpC67PolhWXycADFR2MsMNC3mGESmUv6sR1l6SZ+HgidZrSb+Rrl 8JSlNuJTnCslSs+LlO4k9cFDU9XvedGrQ5pcAr90tUkC+vce6EGlwnlroyTyZPoAzHoV x6bw== X-Forwarded-Encrypted: i=1; AFNElJ9DRvViC6ITzm4m+Fg7JCvsuxEbi200+dJacQImlLpc5Bkpg/Eb2jVK9tLL0l99C0z8KKs1C18=@vger.kernel.org X-Gm-Message-State: AOJu0Yz6Vz727EiQw4JwNur0yY+KnlNJSDpvMQUoE2R4Bg9WnQGhLLmg s/mb0H4RAFUd9WwMoLCy6u+RTZmuR317xg7bOczIkPbN+WfvWlskDFfC X-Gm-Gg: AeBDiesdujf2KDW1ryXS0U5uNzwTYPjIzwwYx8YnKRQ0ioT89dkKevPqzSuj1UsjOpS wCBO4ynBZd0/s/5FGT6S9uptBrWJvlM6aeGVf4lcJb9UO/tgWhag9WVja3umUoxAXmLrSpls1N/ fXWehdHkATwmauJ0CplP/EgMyB2bfEFwPbiUcRr1YF3M9mHrV+qaUbhLWQKA3nd9V+WuzSk3zye JIx95UTHp+UyFtqBRSh//Wl9WFIiQn2802wqnh1m62t+TVEHqDvZSyrfWZj2lLrhGgL+57Ku3qo fyO3mxLdf9iVYTM8okO6xs2akeSrv7FbnYP3LYbiRW4qW0GFLkuHXQzcHBJSnHKgZ9XOR/s9ED6 qqlPV5YRN9kOlhzBjMhEQQw9YFpqWOLlDzmdE/XqD3RULqcsuneNU1uM5VuvhBGdzCoofobAs7K SAbJ+0WNiYklOC59yRzrB7oRF5M3JYqo5pgS3up1Mle3orlesS/1J3Z3x7Mst5nbpYxim+Vl4PY 0apUDp2yPTPNi+CnPGcJ6vH16E7GBhah/R0NYxh1xl1Lha+KlHSr6FBgDWxbmHd9+gplDQ= X-Received: by 2002:a05:600c:34d3:b0:48a:58e1:6d17 with SMTP id 5b1f17b1804b1-48e51f3655emr3935525e9.20.1778002706507; Tue, 05 May 2026 10:38:26 -0700 (PDT) Received: from ahossu.localdomain ([82.78.232.184]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48a82301ad1sm655473875e9.9.2026.05.05.10.38.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 May 2026 10:38:26 -0700 (PDT) From: Alexandru Hossu To: gregkh@linuxfoundation.org Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, error27@gmail.com, luka.gejak@linux.dev, stable@vger.kernel.org Subject: [PATCH v4 1/3] staging: rtl8723bs: fix OOB reads in update_beacon_info() and bwmode_update_check() Date: Tue, 5 May 2026 19:38:16 +0200 Message-ID: <20260505173818.3674164-2-hossu.alexandru@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260505173818.3674164-1-hossu.alexandru@gmail.com> References: <2026050436-italics-clumsy-e83c@gregkh> <20260505173818.3674164-1-hossu.alexandru@gmail.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Four out-of-bounds read paths in Beacon IE processing: 1. Unsigned underflow in len computation. update_beacon_info() computes: len = pkt_len - (_BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN); where len is unsigned int. If pkt_len is smaller than _BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN (36 bytes), the subtraction wraps to a very large value, causing the IE loop to iterate over memory far beyond the receive buffer. Add an early return when pkt_len is too small. 2. IE header and payload may extend past the packet end. The IE loop advances by pIE->length + 2 per iteration but only guards on i < len. When the last IE has only one byte left in the frame, the loop reads pIE->length from pframe[len], one byte past the receive buffer. Even when the header bytes are in bounds, pIE->length can point the data window past len, silently passing a truncated IE to handler functions. Add two guards: break if fewer than sizeof(*pIE) bytes remain, and break if the declared IE payload extends past len. 3. WMM OUI comparison reads 6 bytes past a possibly short IE payload. For WLAN_EID_VENDOR_SPECIFIC, the code calls memcmp(pIE->data, WMM_PARA_OUI, 6) before checking pIE->length == WLAN_WMM_LEN. An IE with pIE->length < 6 causes memcmp to read into adjacent frame data. Swap the condition so the length check comes first. 4. bwmode_update_check() missing minimum IE length check. bwmode_update_check() rejects IEs longer than sizeof(struct HT_info_element) but accepts any shorter length, including zero. After the check it casts pIE->data to struct HT_info_element * and reads infos[0] (offset 1), which is out of bounds when pIE->length is 0 or 1. Change the guard from > to != to require the IE to be exactly the expected size. Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable@vger.kernel.org Signed-off-by: Alexandru Hossu --- Changes in v4: - Add pkt_len < _BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN guard before the len subtraction to prevent unsigned underflow (sashiko review of v3). - Swap WLAN_EID_VENDOR_SPECIFIC condition: check pIE->length == WLAN_WMM_LEN before memcmp to avoid reading 6 bytes from a short IE payload (sashiko review of v3). - Fix bwmode_update_check(): change > sizeof(struct HT_info_element) to != sizeof(struct HT_info_element) to also reject IEs shorter than the expected size, preventing the read of infos[0] on a zero-length IE (sashiko review of v3). Changes in v3: - No code changes from v2. Changes in v2: - Add IE loop header and payload bounds checks in update_beacon_info(). - Use sizeof(*pIE) + pIE->length instead of pIE->length + 2 for consistency with the sizeof(*pIE) guards (Dan Carpenter). drivers/staging/rtl8723bs/core/rtw_wlan_util.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c index 6a7c09db4cd9..7ccfaa538ebb 100644 --- a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c +++ b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c @@ -850,7 +850,7 @@ static void bwmode_update_check(struct adapter *padapter, struct ndis_80211_var_ if (phtpriv->ht_option == false) return; - if (pIE->length > sizeof(struct HT_info_element)) + if (pIE->length != sizeof(struct HT_info_element)) return; pHT_info = (struct HT_info_element *)pIE->data; @@ -1286,15 +1286,23 @@ void update_beacon_info(struct adapter *padapter, u8 *pframe, uint pkt_len, stru unsigned int len; struct ndis_80211_var_ie *pIE; + if (pkt_len < _BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN) + return; + len = pkt_len - (_BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN); for (i = 0; i < len;) { + if (i + sizeof(*pIE) > len) + break; pIE = (struct ndis_80211_var_ie *)(pframe + (_BEACON_IE_OFFSET_ + WLAN_HDR_A3_LEN) + i); + if (i + sizeof(*pIE) + pIE->length > len) + break; switch (pIE->element_id) { case WLAN_EID_VENDOR_SPECIFIC: /* to update WMM parameter set while receiving beacon */ - if (!memcmp(pIE->data, WMM_PARA_OUI, 6) && pIE->length == WLAN_WMM_LEN) /* WMM */ + if (pIE->length == WLAN_WMM_LEN && + !memcmp(pIE->data, WMM_PARA_OUI, 6)) /* WMM */ if (WMM_param_handler(padapter, pIE)) report_wmm_edca_update(padapter); @@ -1314,7 +1322,7 @@ void update_beacon_info(struct adapter *padapter, u8 *pframe, uint pkt_len, stru break; } - i += (pIE->length + 2); + i += sizeof(*pIE) + pIE->length; } } -- 2.53.0