brcmfmac: Fix crash on cleanup.

When driver gets unloaded due to error situation there is a chance
a packet gets received while fws has already been cleaned up. This
will result in kernel crash. This patch adds a check to avoid this
crash.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c b/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c
index d42f7d0..183f08d 100644 (file)
--- a/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c
@@ -1636,7 +1636,7 @@ int brcmf_fws_hdrpull(struct brcmf_pub *drvr, int ifidx, s16 signal_len,
        if (!signal_len)
                return 0;
        /* if flow control disabled, skip to packet data and leave */
-       if (!fws->fw_signals) {
+       if ((!fws) || (!fws->fw_signals)) {
                skb_pull(skb, signal_len);
                return 0;
        }