On Mon, Aug 13, 2012 at 07:43:27PM -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 <[email protected]> > Reported-by: Al Viro <[email protected]> > Signed-off-by: John Fastabend <[email protected]> > --- > > net/core/scm.c | 5 +++++ > 1 files changed, 5 insertions(+), 0 deletions(-) > > diff --git a/net/core/scm.c b/net/core/scm.c > index 8f6ccfd..a14d9e2 100644 > --- a/net/core/scm.c > +++ b/net/core/scm.c > @@ -249,6 +249,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie > *scm) > struct file **fp = scm->fp->fp; > int __user *cmfptr; > int err = 0, i; > + __u32 prioidx = task_netprioidx(current); > > if (MSG_CMSG_COMPAT & msg->msg_flags) { > scm_detach_fds_compat(msg, scm); > @@ -265,6 +266,7 @@ 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 +283,9 @@ 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->sk->sk_cgrp_prioidx = prioidx; nit: You can replace the prioidx variable above and this set with a call to sock_update_netprioidx
Neil -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
