Re: [alsa-devel] [PATCH] rxrpc: Fix uninitialized error code in rxrpc_send_data_packet()

Hi David,

On Fri, May 31, 2019 at 12:35 PM David Howells dhowells@redhat.com wrote:

Here's my take on the patch.

David

rxrpc: Fix uninitialized error code in rxrpc_send_data_packet()

With gcc 4.1:

net/rxrpc/output.c: In function ‘rxrpc_send_data_packet’:
net/rxrpc/output.c:338: warning: ‘ret’ may be used uninitialized in this function

Indeed, if the first jump to the send_fragmentable label is made, and the address family is not handled in the switch() statement, ret will be used uninitialized.

Fix this by BUG()'ing as is done in other places in rxrpc where internal support for future address families will need adding. It should not be possible to reach this normally as the address families are checked up-front.

Fixes: 5a924b8951f835b5 ("rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs") Reported-by: Geert Uytterhoeven geert@linux-m68k.org Signed-off-by: David Howells dhowells@redhat.com

I'm not such a big fan of BUG(), so I'd go for ret = -EAFNOSUPPORT, but given rxrpc is already full of BUG() calls, I guess it is an acceptable solution.

---

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c index 004c762c2e8d..6f2b4fb4b0aa 100644 --- a/net/rxrpc/output.c +++ b/net/rxrpc/output.c @@ -523,6 +523,9 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb, } break; #endif

•   default:
  

•           BUG();
    }
  
    if (ret < 0)
  

Gr{oetje,eeting}s,

Geert