diff mbox

[V2,3/3] brcmfmac: Add check for short event packets

Message ID 20170909193020.19061-3-cernekee@chromium.org (mailing list archive)
State Changes Requested
Delegated to: Kalle Valo
Headers show

Commit Message

Kevin Cernekee Sept. 9, 2017, 7:30 p.m. UTC 
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>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


V1->V2: No change.

Comments

Kalle Valo Sept. 12, 2017, 7:45 a.m. UTC | #1 
Kevin Cernekee <cernekee@chromium.org> wrote:

> 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>
> Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>

I'll queue this for v4.14 and add:

Cc: stable@vger.kernel.org # v3.8+
diff mbox

Patch

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
index 27e661fa356f..28361bb865f3 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
@@ -424,7 +424,8 @@  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())