[net PATCH v2 2/2] net: netprio: fd passed in SCM_RIGHTS datagram not set correctly
From: John Fastabend <hidden>
Date: 2012-08-14 02:59:35
Also in:
lkml
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
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@tuxdriver.com> Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: John Fastabend <redacted> --- 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; fd_install(new_fd, fp[i]); }