From 8654df4e2ac9704905198d63845554c2ddf6a93f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 9 Jun 2016 16:06:06 -0500 Subject: mnt: Refactor fs_fully_visible into mount_too_revealing Replace the call of fs_fully_visible in do_new_mount from before the new superblock is allocated with a call of mount_too_revealing after the superblock is allocated. This winds up being a much better location for maintainability of the code. The first change this enables is the replacement of FS_USERNS_VISIBLE with SB_I_USERNS_VISIBLE. Moving the flag from struct filesystem_type to sb_iflags on the superblock. Unfortunately mount_too_revealing fundamentally needs to touch mnt_flags adding several MNT_LOCKED_XXX flags at the appropriate times. If the mnt_flags did not need to be touched the code could be easily moved into the filesystem specific mount code. Acked-by: Seth Forshee Signed-off-by: "Eric W. Biederman" --- fs/sysfs/mount.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/sysfs') diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index f3db82071cfb..f31e36994dfb 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -42,7 +42,7 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); else if (new_sb) /* Userspace would break if executables appear on sysfs */ - root->d_sb->s_iflags |= SB_I_NOEXEC; + root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE | SB_I_NOEXEC; return root; } @@ -59,7 +59,7 @@ static struct file_system_type sysfs_fs_type = { .name = "sysfs", .mount = sysfs_mount, .kill_sb = sysfs_kill_sb, - .fs_flags = FS_USERNS_VISIBLE | FS_USERNS_MOUNT, + .fs_flags = FS_USERNS_MOUNT, }; int __init sysfs_init(void) -- cgit