re: net-caif: add CAIF core protocol stack
From: Dan Carpenter <hidden>
Date: 2014-12-02 13:41:09
Hello Sjur Braendeland,
The patch b482cd2053e3: "net-caif: add CAIF core protocol stack" from
Mar 30, 2010, leads to the following static checker warning:
net/caif/cfctrl.c:440 cfctrl_recv()
error: potentially using uninitialized 'tmp'.
net/caif/cfpkt_skbuff.c
124 int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len)
125 {
126 struct sk_buff *skb = pkt_to_skb(pkt);
127 u8 *from;
128 if (unlikely(is_erronous(pkt)))
129 return -EPROTO;
130
131 if (unlikely(len > skb->len)) {
132 PKT_ERROR(pkt, "read beyond end of packet\n");
133 return -EPROTO;
134 }
135
136 if (unlikely(len > skb_headlen(skb))) {
^^^^^^^^^^^^^^^^^^^^^
Assume we can hit this condition with "len == 1". I don't know if
that's possible.
137 if (unlikely(skb_linearize(skb) != 0)) {
138 PKT_ERROR(pkt, "linearize failed\n");
139 return -EPROTO;
140 }
141 }
142 from = skb_pull(skb, len);
143 from -= len;
144 if (data)
145 memcpy(data, from, len);
146 return 0;
147 }
148 EXPORT_SYMBOL(cfpkt_extr_head);
net/caif/cfctrl.c
430 case CFCTRL_SRV_RFM:
431 /* Construct a frame, convert
432 * DatagramConnectionID
433 * to network format long and copy it out...
434 */
435 cfpkt_extr_head(pkt, &tmp32, 4);
436 linkparam.u.rfm.connid =
437 le32_to_cpu(tmp32);
438 cp = (u8 *) linkparam.u.rfm.volume;
439 for (cfpkt_extr_head(pkt, &tmp, 1);
440 cfpkt_more(pkt) && tmp != '\0';
^^^^^^^^^^
cfpkt_more() would be true and "tmp" is uninitliazed so it is a forever
loop.
441 cfpkt_extr_head(pkt, &tmp, 1))
442 *cp++ = tmp;
443 *cp = '\0';
regards,
dan carpenter