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| author | Jesper Juhl <jj@chaosbits.net> | 2011-01-13 11:40:11 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-01-13 21:48:26 -0800 |
| commit | 9e56790ad31d72a5a44142af462d047c0c897b29 (patch) | |
| tree | 0557144779a2ad51093110dce0cdc163592e15fb /drivers | |
| parent | e84f885ebfb43b1ebb1481ee8bb2018743f947e9 (diff) | |
| download | linux-9e56790ad31d72a5a44142af462d047c0c897b29.tar.gz linux-9e56790ad31d72a5a44142af462d047c0c897b29.tar.bz2 linux-9e56790ad31d72a5a44142af462d047c0c897b29.zip | |
USB CDC NCM: Don't deref NULL in cdc_ncm_rx_fixup() and don't use uninitialized variable.
skb_clone() dynamically allocates memory and may fail. If it does it
returns NULL. This means we'll dereference a NULL pointer in
drivers/net/usb/cdc_ncm.c::cdc_ncm_rx_fixup().
As far as I can tell, the proper way to deal with this is simply to goto
the error label.
Furthermore gcc complains that 'skb' may be used uninitialized:
drivers/net/usb/cdc_ncm.c: In function ‘cdc_ncm_rx_fixup’:
drivers/net/usb/cdc_ncm.c:922:18: warning: ‘skb’ may be used uninitialized in this function
and I believe it is right. On the line where we
pr_debug("invalid frame detected (ignored)" ...
we are using the local variable 'skb' but nothing has ever been assigned
to that variable yet. I believe the correct fix for that is to use
'skb_in' instead.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/usb/cdc_ncm.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 593c104ab199..d776c4a8d3c1 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1021,13 +1021,15 @@ static int cdc_ncm_rx_fixup(struct usbnet *dev, struct sk_buff *skb_in) (temp > CDC_NCM_MAX_DATAGRAM_SIZE) || (temp < ETH_HLEN)) { pr_debug("invalid frame detected (ignored)" "offset[%u]=%u, length=%u, skb=%p\n", - x, offset, temp, skb); + x, offset, temp, skb_in); if (!x) goto error; break; } else { skb = skb_clone(skb_in, GFP_ATOMIC); + if (!skb) + goto error; skb->len = temp; skb->data = ((u8 *)skb_in->data) + offset; skb_set_tail_pointer(skb, temp); |