From: Alexandru Hossu Date: Fri, 22 May 2026 00:45:28 +0000 (+0200) Subject: staging: rtl8723bs: fix OOB write in HT_caps_handler() X-Git-Tag: v7.2-rc3~2^2~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f8001e1a516ba3b495728c65b61f799cbfad6bd0;p=thirdparty%2Fkernel%2Flinux.git staging: rtl8723bs: fix OOB write in HT_caps_handler() HT_caps_handler() iterates pIE->length bytes and writes into HT_caps.u.HT_cap[], which is a fixed 26-byte array (sizeof struct HT_caps_element). Because pIE->length is a raw u8 from an over-the-air 802.11 AssocResponse frame and is never validated, a malicious AP can set it up to 255, causing up to 229 bytes of out-of-bounds writes into adjacent fields of struct mlme_ext_info. Truncate the iteration count to the size of HT_caps.u.HT_cap using umin() so that data from a longer-than-expected IE is silently ignored rather than written out of bounds, preserving interoperability with APs that pad the element. An early return on oversized IEs was considered but rejected: it would bypass the pmlmeinfo->HT_caps_enable = 1 assignment that precedes the loop, silently disabling HT mode for APs that append extra bytes to the HT Capabilities IE. Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver") Cc: stable Signed-off-by: Alexandru Hossu Reviewed-by: Luka Gejak Link: https://patch.msgid.link/20260522004531.1038924-5-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 b355d8a3ceab..4c0eb93f412e 100644 --- a/drivers/staging/rtl8723bs/core/rtw_wlan_util.c +++ b/drivers/staging/rtl8723bs/core/rtw_wlan_util.c @@ -909,7 +909,8 @@ void HT_caps_handler(struct adapter *padapter, struct ndis_80211_var_ie *pIE) pmlmeinfo->HT_caps_enable = 1; - for (i = 0; i < (pIE->length); i++) { + for (i = 0; i < umin(pIE->length, + sizeof(pmlmeinfo->HT_caps.u.HT_cap)); i++) { if (i != 2) { /* Commented by Albert 2010/07/12 */ /* Got the endian issue here. */