Messages in this thread Patch in this message | | | Date | Wed, 24 Jun 2020 13:44:37 +0200 | From | Michal Koutný <> | Subject | Re: [PATCH v4 2/3] nsproxy: attach to namespaces via pidfds |
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Hi.
On Tue, May 05, 2020 at 04:04:31PM +0200, Christian Brauner <christian.brauner@ubuntu.com> wrote: > -SYSCALL_DEFINE2(setns, int, fd, int, nstype) > +SYSCALL_DEFINE2(setns, int, fd, int, flags) > [...] > - file = proc_ns_fget(fd); > - if (IS_ERR(file)) > - return PTR_ERR(file); > + int err = 0; > > - err = -EINVAL; > - ns = get_proc_ns(file_inode(file)); > - if (nstype && (ns->ops->type != nstype)) > + file = fget(fd); > + if (!file) > + return -EBADF; > + > + if (proc_ns_file(file)) { > + ns = get_proc_ns(file_inode(file)); > + if (flags && (ns->ops->type != flags)) > + err = -EINVAL; > + flags = ns->ops->type; > + } else if (pidfd_pid(file)) { > + err = check_setns_flags(flags); > + } else { > + err = -EBADF; > + } > + if (err) > goto out; > > - err = prepare_nsset(ns->ops->type, &nsset); > + err = prepare_nsset(flags, &nsset); > if (err) > goto out; This modification changed the returned error when a valid file descriptor is passed but it doesn't represent a namespace (nor pidfd). The error is now EBADF although originally and per man page it was/should be EINVAL.
A change like below would restore it, however, I see it may be less consistent with other pidfd calls(?), then I'd suggest updating the manpage to capture this.
--- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -531,7 +531,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, flags) } else if (!IS_ERR(pidfd_pid(file))) { err = check_setns_flags(flags); } else { - err = -EBADF; + err = -EINVAL; } if (err) goto out; I noticed this breaks systemd self tests [1].
Regards, Michal
[1] https://github.com/systemd/systemd/blob/a1ba8c5b71164665ccb53c9cec384e5eef7d3689/src/test/test-seccomp.c#L246 [unhandled content-type:application/pgp-signature] | |