brcmfmac: Avoid possible out-of-bounds read

In brcmf_p2p_notify_rx_mgmt_p2p_probereq(), chanspec is assigned before
the length of rxframe is validated.  This could lead to uninitialized
data being accessed (but not printed).  Since we already have a
perfectly good endian-swapped copy of rxframe->chanspec in ch.chspec,
and ch.chspec is not modified by decchspec(), avoid the extra
assignment and use ch.chspec in the debug print.

Suggested-by: Mattias Nissler <mnissler@chromium.org>
Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index 2ce675a..1c450c0 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -1853,7 +1853,6 @@ s32 brcmf_p2p_notify_rx_mgmt_p2p_probereq(struct brcmf_if *ifp,
        struct afx_hdl *afx_hdl = &p2p->afx_hdl;
        struct brcmf_cfg80211_vif *vif = ifp->vif;
        struct brcmf_rx_mgmt_data *rxframe = (struct brcmf_rx_mgmt_data *)data;
-       u16 chanspec = be16_to_cpu(rxframe->chanspec);
        struct brcmu_chan ch;
        u8 *mgmt_frame;
        u32 mgmt_frame_len;
@@ -1906,7 +1905,7 @@ s32 brcmf_p2p_notify_rx_mgmt_p2p_probereq(struct brcmf_if *ifp,
        cfg80211_rx_mgmt(&vif->wdev, freq, 0, mgmt_frame, mgmt_frame_len, 0);
 
        brcmf_dbg(INFO, "mgmt_frame_len (%d) , e->datalen (%d), chanspec (%04x), freq (%d)\n",
-                 mgmt_frame_len, e->datalen, chanspec, freq);
+                 mgmt_frame_len, e->datalen, ch.chspec, freq);
 
        return 0;
 }