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; fd_install(new_fd, fp[i]); } -- 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/
