From: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>
A socket fd passed in a SCM_RIGHTS datagram was not getting
updated with the new tasks cgrp classid. This leaves IO on
the socket tagged with the old tasks classid.
To fix this add a check in the scm recvmsg path to update the
sock cgrp classid with the new tasks value.
Signed-off-by: Daniel Wagner <daniel.wagner@xxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Cc: John Fastabend <john.r.fastabend@xxxxxxxxx>
Cc: Neil Horman <nhorman@xxxxxxxxxxxxx>
Cc: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: cgroups@xxxxxxxxxxxxxxx
---
net/core/scm.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/core/scm.c b/net/core/scm.c
index 8f6ccfd..221080f 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -35,7 +35,7 @@
#include <net/sock.h>
#include <net/compat.h>
#include <net/scm.h>
-
+#include <net/cls_cgroup.h>
/*
* Only allow a user to send credentials, that they could set with
@@ -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 classid = task_cls_classid(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)
@@ -282,6 +284,9 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm)
/* Bump the usage count and install the file. */
get_file(fp[i]);
fd_install(new_fd, fp[i]);
+ sock = sock_from_file(fp[i], &err);
+ if (sock)
+ sock->sk->sk_classid = classid;
}
if (i > 0)
--
1.7.12.rc1.16.g05a20c8
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