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 <nhor...@tuxdriver.com>
Reported-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: John Fastabend <john.r.fastab...@intel.com>
---
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..053bd43 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)
@@ -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_cgrp_prioidx = prioidx;
}
if (i > 0)
--
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