brcmfmac: Add check for short event packets

BugLink: http://bugs.launchpad.net/bugs/1731951
commit dd2349121bb1b8ff688c3ca6a2a0bea9d8c142ca upstream.

The length of the data in the received skb is currently passed into
brcmf_fweh_process_event() as packet_len, but this value is not checked.
event_packet should be followed by DATALEN bytes of additional event
data.  Ensure that the received packet actually contains at least
DATALEN bytes of additional data, to avoid copying uninitialized memory
into event->data.

Suggested-by: Mattias Nissler <mnissler@chromium.org>
Signed-off-by: Kevin Cernekee <cernekee@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index 4eb1e1ce9aceccc9214657fa6081ba5327c021ca..ef72baf6dd969c2478a2138ea57b9f691fdf12d8 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
@@ -429,7 +429,8 @@ void brcmf_fweh_process_event(struct brcmf_pub *drvr,
        if (code != BRCMF_E_IF && !fweh->evt_handler[code])
                return;
 
-       if (datalen > BRCMF_DCMD_MAXLEN)
+       if (datalen > BRCMF_DCMD_MAXLEN ||
+           datalen + sizeof(*event_packet) > packet_len)
                return;
 
        if (in_interrupt())