Fix rxrpc_connect_call() to return -ENOMEM rather than 0 if it fails to
look up a peer.

This generated a smatch warning:
        net/rxrpc/call_object.c:303 rxrpc_connect_call() warn: missing error code 'ret'

I think this also fixes a syzbot-found bug:

        rxrpc: Assertion failed - 1(0x1) == 11(0xb) is false
        ------------[ cut here ]------------
        kernel BUG at net/rxrpc/call_object.c:645!

where the call being put is in the wrong state - as would be the case if we
failed to clear up correctly after the error in rxrpc_connect_call().

Fixes: 9d35d880e0e4 ("rxrpc: Move client call connection to the I/O thread")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-and-tested-by: syzbot+4bb6356bb29d6299360e@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/202301111153.9eZRYLf1-lkp@intel.com/
---
 net/rxrpc/call_object.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 3ded5a24627c..f3c9f0201c15 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -294,7 +294,7 @@ static void rxrpc_put_call_slot(struct rxrpc_call *call)
 static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
 {
 	struct rxrpc_local *local = call->local;
-	int ret = 0;
+	int ret = -ENOMEM;
 
 	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
 

On Wed, 11 Jan 2023 18:07:15 +0000 David Howells wrote:
> Fix rxrpc_connect_call() to return -ENOMEM rather than 0 if it fails to
> look up a peer.
> 
> This generated a smatch warning:
>         net/rxrpc/call_object.c:303 rxrpc_connect_call() warn: missing error code 'ret'
> 
> I think this also fixes a syzbot-found bug:
> 
>         rxrpc: Assertion failed - 1(0x1) == 11(0xb) is false
>         ------------[ cut here ]------------
>         kernel BUG at net/rxrpc/call_object.c:645!
> 
> where the call being put is in the wrong state - as would be the case if we
> failed to clear up correctly after the error in rxrpc_connect_call().

Applied, thanks!

On Wed, 2023-01-11 at 18:07 +0000, David Howells wrote:
>     
> Fix rxrpc_connect_call() to return -ENOMEM rather than 0 if it fails to
> look up a peer.
> 
> This generated a smatch warning:
>         net/rxrpc/call_object.c:303 rxrpc_connect_call() warn: missing error code 'ret'
> 
> I think this also fixes a syzbot-found bug:
> 
>         rxrpc: Assertion failed - 1(0x1) == 11(0xb) is false
>         ------------[ cut here ]------------
>         kernel BUG at net/rxrpc/call_object.c:645!
> 
> where the call being put is in the wrong state - as would be the case if we
> failed to clear up correctly after the error in rxrpc_connect_call().
> 
> Fixes: 9d35d880e0e4 ("rxrpc: Move client call connection to the I/O thread")
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Reported-and-tested-by: syzbot+4bb6356bb29d6299360e@syzkaller.appspotmail.com
> Signed-off-by: David Howells <dhowells@redhat.com>
> Link: https://lore.kernel.org/r/202301111153.9eZRYLf1-lkp@intel.com/
> ---
>  net/rxrpc/call_object.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
> index 3ded5a24627c..f3c9f0201c15 100644
> --- a/net/rxrpc/call_object.c
> +++ b/net/rxrpc/call_object.c
> @@ -294,7 +294,7 @@ static void rxrpc_put_call_slot(struct rxrpc_call *call)
>  static int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
>  {
>  	struct rxrpc_local *local = call->local;
> -	int ret = 0;
> +	int ret = -ENOMEM;
>  
>  	_enter("{%d,%lx},", call->debug_id, call->user_call_ID);
>  

Looks good to me.

Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>