Re: [ammarfaizi2-block:dhowells/linux-fs/rxrpc-ringless-5 29/79] net/rxrpc/io_thread.c:52 rxrpc_error_report() error: uninitialized symbol 'skb'.

[Dan Carpenter <error27@gmail.com>]

On Wed, Nov 16, 2022 at 01:57:43PM +0000, David Howells wrote:
> Dan Carpenter <error27@gmail.com> wrote:
> 
> > New smatch warnings:
> > net/rxrpc/io_thread.c:52 rxrpc_error_report() error: uninitialized symbol 'skb'.
> 
> Fixed that.
> 
> > Old smatch warnings:
> > net/rxrpc/io_thread.c:210 rxrpc_input_packet() warn: passing freed memory 'skb'
> 
> Do you know if that's still there?  "Old" in what sense?
> 

The file name has changed so it took me a while to track this down.
This is fine.  The "skb" pointer here is just used for tracing and not
dereferenced.

net/rxrpc/input.c
   563          /* Unshare the packet so that it can be modified for in-place
   564           * decryption.
   565           */
   566          if (sp->hdr.securityIndex != 0) {
   567                  struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
                                                           ^^^
There is still a reference to "skb" somewhere but we drop ours.

   568                  if (!nskb) {
   569                          rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
                                                ^^^
This would be a bug if it were dereferenced but it's just tracing stuff
that doesn't dereference the "skb" pointer.

   570                          return;
   571                  }
   572  
   573                  if (nskb != skb) {
   574                          rxrpc_eaten_skb(skb, rxrpc_skb_received);
   575                          skb = nskb;
   576                          rxrpc_new_skb(skb, rxrpc_skb_unshared);
   577                          sp = rxrpc_skb(skb);
   578                  }
   579          }

regards,
dan carpenter