Re: [PATCH] net: fix oops in socket ioctl cmd SIOCGSKNS when NET_NS is disabled
From: Cong Wang <hidden>
Date: 2021-05-29 19:15:12
Also in:
lkml, stable
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
On Fri, May 28, 2021 at 11:08 PM Changbin Du [off-list ref] wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/socket.c b/net/socket.c index 27e3e7d53f8e..644b46112d35 100644 --- a/net/socket.c +++ b/net/socket.c@@ -1149,11 +1149,15 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg) mutex_unlock(&vlan_ioctl_mutex); break; case SIOCGSKNS: +#ifdef CONFIG_NET_NS err = -EPERM; if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) break; err = open_related_ns(&net->ns, get_net_ns); +#else + err = -ENOTSUPP; +#endif
I wonder if it is easier if we just reject ns->ops==NULL case in open_related_ns(). For 1) we can save an ugly #ifdef here; 2) drivers/net/tun.c has the same bugs. Something like this:
diff --git a/fs/nsfs.c b/fs/nsfs.c
index 800c1d0eb0d0..d63414604e99 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c@@ -152,6 +152,9 @@ int open_related_ns(struct ns_common *ns, int err; int fd; + if (!ns->ops) + return -EOPNOTSUPP; + fd = get_unused_fd_flags(O_CLOEXEC); if (fd < 0) return fd;