On Wed, May 13, 2020 at 11:49:08AM +0200, Christoph Hellwig wrote: > On Wed, May 13, 2020 at 12:29:18PM +0300, Ido Schimmel wrote: > > On Mon, May 11, 2020 at 01:59:12PM +0200, Christoph Hellwig wrote: > > > Factor out two helpes to keep the code tidy. > > > > > > Signed-off-by: Christoph Hellwig <h...@lst.de> > > > > Christoph, > > > > After installing net-next (fb9f2e92864f) on a Fedora 32 machine I cannot > > ssh to it. Bisected it to this commit [1]. > > > > When trying to connect I see these error messages in journal: > > > > sshd[1029]: error: mm_receive_fd: no message header > > sshd[1029]: fatal: mm_pty_allocate: receive fds failed > > sshd[1029]: fatal: mm_request_receive_expect: buffer error: incomplete > > message > > sshd[1018]: fatal: mm_request_receive: read: Connection reset by peer > > > > Please let me know if more info is required. I can easily test a patch > > if you need me to try something. > > To start we can try reverting just this commit, which requires a > little manual work. Patch below:
Thanks for the quick reply. With the below patch ssh is working again. > > --- > From fe4f53219b42aeded3c1464dbe2bbc9365f6a853 Mon Sep 17 00:00:00 2001 > From: Christoph Hellwig <h...@lst.de> > Date: Wed, 13 May 2020 11:48:33 +0200 > Subject: Revert "net/scm: cleanup scm_detach_fds" > > This reverts commit 2618d530dd8b7ac0fdcb83f4c95b88f7b0d37ce6. > --- > net/core/scm.c | 94 +++++++++++++++++++++++--------------------------- > 1 file changed, 43 insertions(+), 51 deletions(-) > > diff --git a/net/core/scm.c b/net/core/scm.c > index a75cd637a71ff..2d9aa5682bed2 100644 > --- a/net/core/scm.c > +++ b/net/core/scm.c > @@ -280,53 +280,18 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, > struct scm_timestamping_inter > } > EXPORT_SYMBOL(put_cmsg_scm_timestamping); > > -static int __scm_install_fd(struct file *file, int __user *ufd, int o_flags) > -{ > - struct socket *sock; > - int new_fd; > - int error; > - > - error = security_file_receive(file); > - if (error) > - return error; > - > - new_fd = get_unused_fd_flags(o_flags); > - if (new_fd < 0) > - return new_fd; > - > - error = put_user(new_fd, ufd); > - if (error) { > - put_unused_fd(new_fd); > - return error; > - } > - > - /* Bump the usage count and install the file. */ > - sock = sock_from_file(file, &error); > - if (sock) { > - sock_update_netprioidx(&sock->sk->sk_cgrp_data); > - sock_update_classid(&sock->sk->sk_cgrp_data); > - } > - fd_install(new_fd, get_file(file)); > - return error; > -} > - > -static int scm_max_fds(struct msghdr *msg) > -{ > - if (msg->msg_controllen <= sizeof(struct cmsghdr)) > - return 0; > - return (msg->msg_controllen - sizeof(struct cmsghdr)) / sizeof(int); > -} > - > void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) > { > struct cmsghdr __user *cm > = (__force struct cmsghdr __user*)msg->msg_control; > - int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; > - int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count); > - int __user *cmsg_data = CMSG_USER_DATA(cm); > + > + int fdmax = 0; > + int fdnum = scm->fp->count; > + struct file **fp = scm->fp->fp; > + int __user *cmfptr; > int err = 0, i; > > - if (msg->msg_flags & MSG_CMSG_COMPAT) { > + if (MSG_CMSG_COMPAT & msg->msg_flags) { > scm_detach_fds_compat(msg, scm); > return; > } > @@ -335,35 +300,62 @@ void scm_detach_fds(struct msghdr *msg, struct > scm_cookie *scm) > if (WARN_ON_ONCE(!msg->msg_control_is_user)) > return; > > - for (i = 0; i < fdmax; i++) { > - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); > + if (msg->msg_controllen > sizeof(struct cmsghdr)) > + fdmax = ((msg->msg_controllen - sizeof(struct cmsghdr)) > + / sizeof(int)); > + > + if (fdnum < fdmax) > + fdmax = fdnum; > + > + for (i=0, cmfptr =(int __user *)CMSG_USER_DATA(cm); i<fdmax; > + i++, cmfptr++) > + { > + struct socket *sock; > + int new_fd; > + err = security_file_receive(fp[i]); > if (err) > break; > + err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & msg->msg_flags > + ? O_CLOEXEC : 0); > + if (err < 0) > + break; > + new_fd = err; > + err = put_user(new_fd, cmfptr); > + if (err) { > + put_unused_fd(new_fd); > + break; > + } > + /* Bump the usage count and install the file. */ > + sock = sock_from_file(fp[i], &err); > + if (sock) { > + sock_update_netprioidx(&sock->sk->sk_cgrp_data); > + sock_update_classid(&sock->sk->sk_cgrp_data); > + } > + fd_install(new_fd, get_file(fp[i])); > } > > - if (i > 0) { > - int cmlen = CMSG_LEN(i * sizeof(int)); > - > + if (i > 0) > + { > + int cmlen = CMSG_LEN(i*sizeof(int)); > err = put_user(SOL_SOCKET, &cm->cmsg_level); > if (!err) > err = put_user(SCM_RIGHTS, &cm->cmsg_type); > if (!err) > err = put_user(cmlen, &cm->cmsg_len); > if (!err) { > - cmlen = CMSG_SPACE(i * sizeof(int)); > + cmlen = CMSG_SPACE(i*sizeof(int)); > if (msg->msg_controllen < cmlen) > cmlen = msg->msg_controllen; > msg->msg_control += cmlen; > msg->msg_controllen -= cmlen; > } > } > - > - if (i < scm->fp->count || (scm->fp->count && fdmax <= 0)) > + if (i < fdnum || (fdnum && fdmax <= 0)) > msg->msg_flags |= MSG_CTRUNC; > > /* > - * All of the files that fit in the message have had their usage counts > - * incremented, so we just free the list. > + * All of the files that fit in the message have had their > + * usage counts incremented, so we just free the list. > */ > __scm_destroy(scm); > } > -- > 2.26.2 >