From: Alexandru Hossu Date: Fri, 22 May 2026 00:45:25 +0000 (+0200) Subject: staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop X-Git-Tag: v7.2-rc3~2^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ed51de4a86e173c3b0ef78e039c2e49e08b11f16;p=thirdparty%2Fkernel%2Flinux.git staging: rtl8723bs: fix OOB read in update_beacon_info() IE loop The IE parsing loop in update_beacon_info() advances by (pIE->length + 2) each iteration but only guards on i < len. When a malicious AP sends a Beacon whose last IE has only one byte remaining in the frame (the element_id byte lands at len-1), the loop reads pIE->length from one byte past the allocated receive buffer. Additionally, even when the header bytes are in bounds, pIE->length itself can extend the data window beyond len, passing a truncated IE to the handler functions. Add two guards at the top of the loop body: 1. Break if fewer than sizeof(*pIE) bytes remain (can't read header). 2. Break if the IE's declared data extends past len. Also replace i += (pIE->length + 2) with i += sizeof(*pIE) + pIE->length for consistency with the sizeof(*pIE) guards added above. Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable Reviewed-by: Luka Gejak Signed-off-by: Alexandru Hossu Link: https://patch.msgid.link/20260522004531.1038924-2-hossu.alexandru@gmail.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c index 1d37c2d5b10d..b355d8a3ceab 100644 --- a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c +++ b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c @@ -1262,7 +1262,11 @@ void update_beacon_info(struct adapter *padapter, u8 *pframe, uint pkt_len, stru 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: @@ -1287,7 +1291,7 @@ void update_beacon_info(struct adapter *padapter, u8 *pframe, uint pkt_len, stru break; } - i += (pIE->length + 2); + i += sizeof(*pIE) + pIE->length; } }