From: Yi Cong In recvframe_chk_defrag(), when a fragment's transmitter address is unknown (no associated station) and the frame is not a data frame, the code looks up the broadcast/multicast station with rtw_get_bcmc_stainfo() and immediately dereferences the result to obtain defrag_q, without a NULL check. rtw_get_bcmc_stainfo() (a thin wrapper around rtw_get_stainfo()) can return NULL, for example if the bcmc station has not been or is no longer allocated. Every other call site of rtw_get_bcmc_stainfo() in the driver checks the return value; this one was missed. A fragment with an unknown transmitter address received from the network (e.g. an injected/rogue management fragment) could thus trigger a NULL pointer dereference panic. Check the return value and set pdefrag_q = NULL when no bcmc station is available, consistent with the adjacent data-frame branch (the later code already handles pdefrag_q == NULL). Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver") Assisted-by: GLM:5.2 Signed-off-by: Yi Cong --- drivers/staging/rtl8723bs/core/rtw_recv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/staging/rtl8723bs/core/rtw_recv.c b/drivers/staging/rtl8723bs/core/rtw_recv.c index 86c5e2c4e7ddd..ffcee431caf55 100644 --- a/drivers/staging/rtl8723bs/core/rtw_recv.c +++ b/drivers/staging/rtl8723bs/core/rtw_recv.c @@ -1146,7 +1146,10 @@ static union recv_frame *recvframe_chk_defrag(struct adapter *padapter, union re if (type != WIFI_DATA_TYPE) { psta = rtw_get_bcmc_stainfo(padapter); - pdefrag_q = &psta->sta_recvpriv.defrag_q; + if (psta) + pdefrag_q = &psta->sta_recvpriv.defrag_q; + else + pdefrag_q = NULL; } else { pdefrag_q = NULL; } -- 2.25.1