[PATCH 5.15 161/570] staging: rtl8723bs: fix potential out-of-bounds read in rtw_restruct_wmm_ie

Greg Kroah-Hartman
2026-04-13T16:26:24Z

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

commit a75281626fc8fa6dc6c9cc314ee423e8bc45203b upstream.

The current code checks 'i + 5 < in_len' at the end of the if statement.
However, it accesses 'in_ie[i + 5]' before that check, which can lead
to an out-of-bounds read. Move the length check to the beginning of the
conditional to ensure the index is within bounds before accessing the
array.

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Signed-off-by: Luka Gejak <luka.gejak@linux.dev>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20260224132647.11642-2-luka.gejak@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/rtl8723bs/core/rtw_mlme.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/staging/rtl8723bs/core/rtw_mlme.c
+++ b/drivers/staging/rtl8723bs/core/rtw_mlme.c
@@ -2008,7 +2008,10 @@ int rtw_restruct_wmm_ie(struct adapter *
while (i < in_len) {
ielength = initial_out_len;

- if (in_ie[i] == 0xDD && in_ie[i+2] == 0x00 && in_ie[i+3] == 0x50 && in_ie[i+4] == 0xF2 && in_ie[i+5] == 0x02 && i+5 < in_len) { /* WMM element ID and OUI */
+ if (i + 5 < in_len &&
+ in_ie[i] == 0xDD && in_ie[i + 2] == 0x00 &&
+ in_ie[i + 3] == 0x50 && in_ie[i + 4] == 0xF2 &&
+ in_ie[i + 5] == 0x02) {
for (j = i; j < i + 9; j++) {
out_ie[ielength] = in_ie[j];
ielength++;