[CFT][PATCH 03/10] vfs: Ignore unlocked mounts in fs_fully_visible
From: Eric W. Biederman <hidden>
Date: 2015-05-16 02:07:29
Also in:
linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2015-05-14 · [CFT][PATCH 03/10] vfs: Ignore unlocked mounts in fs_fully_visible · Eric W. Biederman <hidden>
Limit the mounts fs_fully_visible considers to locked mounts. Unlocked can always be unmounted so considering them adds hassle but no security benefit. Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> --- fs/namespace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index fccee9924e8c..3ede0669b8d2 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c@@ -3211,11 +3211,15 @@ static bool fs_fully_visible(struct file_system_type *type, int *new_mnt_flags) ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (new_flags & MNT_ATIME_MASK))) continue; - /* This mount is not fully visible if there are any child mounts - * that cover anything except for empty directories. + /* This mount is not fully visible if there are any + * locked child mounts that cover anything except for + * empty directories. */ list_for_each_entry(child, &mnt->mnt_mounts, mnt_child) { struct inode *inode = child->mnt_mountpoint->d_inode; + /* Only worry about locked mounts */ + if (!(mnt->mnt.mnt_flags & MNT_LOCKED)) + continue; if (!S_ISDIR(inode->i_mode)) goto next; if (inode->i_nlink > 2)
--
2.2.1