[PATCH] staging: rtl8723bs: fix remote heap information disclosure in issue_assocreq

luka.gejak
2026-04-14T19:50:38Z

From: Luka Gejak <luka.gejak@linux.dev>

When building an association request frame, the driver copies the
ht capability ie using the attacker-controlled pIE->length from the
ap's beacon. If the ap provides a length greater than the size of
struct HT_caps_element (26 bytes), it causes an out-of-bounds read
of the adjacent heap memory (HT_info and network structures).
This uninitialized or sensitive memory is then transmitted over the air,
resulting in a remote heap information disclosure.

Fix this by clamping the length passed to rtw_set_ie() to the actual
size of struct HT_caps_element.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Luka Gejak <luka.gejak@linux.dev>
---
Note: Note: Alignment of arguments in rtw_set_ie() is intentionally
like that to avoid WARNING: line length of 105 exceeds 100 columns.

drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
index 5f00fe282d1b..a5f30c3fd47e 100644
--- a/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
+++ b/drivers/staging/rtl8723bs/core/rtw_mlme_ext.c
@@ -2954,7 +2954,9 @@ void issue_assocreq(struct adapter *padapter)
if (padapter->mlmepriv.htpriv.ht_option) {
if (!(is_ap_in_tkip(padapter))) {
memcpy(&(pmlmeinfo->HT_caps), pIE->data, sizeof(struct HT_caps_element));
- pframe = rtw_set_ie(pframe, WLAN_EID_HT_CAPABILITY, pIE->length, (u8 *)(&(pmlmeinfo->HT_caps)), &(pattrib->pktlen));
+ pframe = rtw_set_ie(pframe, WLAN_EID_HT_CAPABILITY,
+ min_t(uint, pIE->length, sizeof(struct HT_caps_element)),
+ (u8 *)&pmlmeinfo->HT_caps, &pattrib->pktlen);
}
}
break;
--
2.53.0