Re: [net PATCH v3 2/3] net: netprio: fd passed in SCM_RIGHTSdatagram not set correctly

[Neil Horman]

On Tue, Aug 14, 2012 at 03:34:30PM -0700, John Fastabend wrote:
> A socket fd passed in a SCM_RIGHTS datagram was not getting
> updated with the new tasks cgrp prioidx. This leaves IO on
> the socket tagged with the old tasks priority.
> 
> To fix this add a check in the scm recvmsg path to update the
> sock cgrp prioidx with the new tasks value.
> 
> Thanks to Al Viro for catching this.
> 
> CC: Neil Horman <nhorman@xxxxxxxxxxxxx>
> Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: John Fastabend <john.r.fastabend@xxxxxxxxx>
> ---
> 
>  net/core/scm.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/net/core/scm.c b/net/core/scm.c
> index 8f6ccfd..040cebe 100644
> --- a/net/core/scm.c
> +++ b/net/core/scm.c
> @@ -265,6 +265,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
>  	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;
>  	     i++, cmfptr++)
>  	{
> +		struct socket *sock;
>  		int new_fd;
>  		err = security_file_receive(fp[i]);
>  		if (err)
> @@ -281,6 +282,9 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
>  		}
>  		/* Bump the usage count and install the file. */
>  		get_file(fp[i]);
> +		sock = sock_from_file(fp[i], &err);
> +		if (sock)
> +			sock_update_netprioidx(sock->sk, current);
>  		fd_install(new_fd, fp[i]);
>  	}
>  
> 
> 

Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>

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