Re: [PATCH] USB CDC NCM: Don't deref NULL in cdc_ncm_rx_fixup() and don't use uninitialized variable.
flat view
From: David Miller <davem@davemloft.net>
Date: 2011-01-14 05:50:01
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lkml
From: Jesper Juhl <redacted> Date: Thu, 13 Jan 2011 22:40:11 +0100 (CET)
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 <redacted>Applied.