Re: net/dsa/tag_sja1105.c:432 sja1105_rcv() error: uninitialized symbol 'vid'.

[Dan Carpenter <dan.carpenter@oracle.com>]

On Wed, Apr 27, 2022 at 01:51:28PM +0000, Vladimir Oltean wrote:
> On Wed, Apr 27, 2022 at 10:13:30AM +0300, Dan Carpenter wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  master
> > head:   cf424ef014ac30b0da27125dd1fbdf10b0d3a520
> > commit: 04a1758348a87eb73b8a4554d0c227831e2bb33e net: dsa: tag_sja1105: fix control packets on SJA1110 being received on an imprecise port
> > config: openrisc-randconfig-m031-20220425 (https://download.01.org/0day-ci/archive/20220427/202204270649.Eun9P40C-lkp@intel.com/config )
> > compiler: or1k-linux-gcc (GCC) 11.2.0
> > 
> > If you fix the issue, kindly add following tag as appropriate
> > Reported-by: kernel test robot <lkp@intel.com>
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > New smatch warnings:
> > net/dsa/tag_sja1105.c:432 sja1105_rcv() error: uninitialized symbol 'vid'.
> > 
> > Old smatch warnings:
> > net/dsa/tag_sja1105.c:564 sja1110_rcv() error: uninitialized symbol 'vid'.
> > 
> > vim +/vid +432 net/dsa/tag_sja1105.c
> > 
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  393  static struct sk_buff *sja1105_rcv(struct sk_buff *skb,
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  394  				   struct net_device *netdev,
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  395  				   struct packet_type *pt)
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  396  {
> > 884be12f85666c6 Vladimir Oltean 2021-07-26  397  	int source_port = -1, switch_id = -1;
> > e53e18a6fe4d3ae Vladimir Oltean 2019-06-08  398  	struct sja1105_meta meta = {0};
> > e80f40cbe4dd513 Vladimir Oltean 2020-03-24  399  	struct ethhdr *hdr;
> > 42824463d38d273 Vladimir Oltean 2019-06-08  400  	bool is_link_local;
> > e53e18a6fe4d3ae Vladimir Oltean 2019-06-08  401  	bool is_meta;
> > 884be12f85666c6 Vladimir Oltean 2021-07-26  402  	u16 vid;
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  403  
> > e80f40cbe4dd513 Vladimir Oltean 2020-03-24  404  	hdr = eth_hdr(skb);
> > 42824463d38d273 Vladimir Oltean 2019-06-08  405  	is_link_local = sja1105_is_link_local(skb);
> > e53e18a6fe4d3ae Vladimir Oltean 2019-06-08  406  	is_meta = sja1105_is_meta_frame(skb);
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  407  
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  408  	skb->offload_fwd_mark = 1;
> > 227d07a07ef1262 Vladimir Oltean 2019-05-05  409  
> > 233697b3b3f60b1 Vladimir Oltean 2021-06-11  410  	if (sja1105_skb_has_tag_8021q(skb)) {
> > 42824463d38d273 Vladimir Oltean 2019-06-08  411  		/* Normal traffic path. */
> > 04a1758348a87eb Vladimir Oltean 2021-07-29  412  		sja1105_vlan_rcv(skb, &source_port, &switch_id, &vid);
> > 
> > There is a return where *vid is not set
> 
> And also one where source_port and switch_id are left with their default
> values of -1.
> 

I should probably have wondered why I hadn't emailed you before...  For
some reason I got confused and thought it was an arch/ thing...

My desktop build does cross function analysis so it doesn't print this
false positive.

regards,
dan carpenter