From 38292407c2bb5b2b3131aaace4ecc7a829b40b76 Mon Sep 17 00:00:00 2001 From: Navaneeth K Date: Thu, 20 Nov 2025 16:35:20 +0000 Subject: [PATCH] staging: rtl8723bs: fix out-of-bounds read in OnBeacon ESR IE parsing commit 502ddcc405b69fa92e0add6c1714d654504f6fd7 upstream. The Extended Supported Rates (ESR) IE handling in OnBeacon accessed *(p + 1 + ielen) and *(p + 2 + ielen) without verifying that these offsets lie within the received frame buffer. A malformed beacon with an ESR IE positioned at the end of the buffer could cause an out-of-bounds read, potentially triggering a kernel panic. Add a boundary check to ensure that the ESR IE body and the subsequent bytes are within the limits of the frame before attempting to access them. This prevents OOB reads caused by malformed beacon frames. Signed-off-by: Navaneeth K Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c index 7d451cd5835a2..32aa168bcb075 100644 --- a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c +++ b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c @@ -579,9 +579,11 @@ unsigned int OnBeacon(struct adapter *padapter, union recv_frame *precv_frame) p = rtw_get_ie(pframe + sizeof(struct ieee80211_hdr_3addr) + _BEACON_IE_OFFSET_, WLAN_EID_EXT_SUPP_RATES, &ielen, precv_frame->u.hdr.len - sizeof(struct ieee80211_hdr_3addr) - _BEACON_IE_OFFSET_); if (p && ielen > 0) { - if ((*(p + 1 + ielen) == 0x2D) && (*(p + 2 + ielen) != 0x2D)) - /* Invalid value 0x2D is detected in Extended Supported Rates (ESR) IE. Try to fix the IE length to avoid failed Beacon parsing. */ - *(p + 1) = ielen - 1; + if (p + 2 + ielen < pframe + len) { + if ((*(p + 1 + ielen) == 0x2D) && (*(p + 2 + ielen) != 0x2D)) + /* Invalid value 0x2D is detected in Extended Supported Rates (ESR) IE. Try to fix the IE length to avoid failed Beacon parsing. */ + *(p + 1) = ielen - 1; + } } if (pmlmeext->sitesurvey_res.state == SCAN_PROCESS) { -- 2.47.3