diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2015-01-07 08:10:09 -0600 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-07-20 21:12:43 -0400 |
| commit | e4102c423958dc4c88a5e4062f66976974709a6d (patch) | |
| tree | 1cef2e26e18af9b01f94504873816dcf67274834 /fs | |
| parent | 4f2e3f88a6fae8882371378d1d1cb493ca51a50c (diff) | |
| download | lwn-e4102c423958dc4c88a5e4062f66976974709a6d.tar.gz lwn-e4102c423958dc4c88a5e4062f66976974709a6d.zip | |
vfs: Ignore unlocked mounts in fs_fully_visible
[ Upstream commit c89d4319ae55186496c43b7a6e510aa1d09dd387 ]
commit ceeb0e5d39fcdf4dca2c997bf225c7fc49200b37 upstream.
Limit the mounts fs_fully_visible considers to locked mounts.
Unlocked can always be unmounted so considering them adds hassle
but no security benefit.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 6dff37327f68..da23ad8a2c85 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3166,11 +3166,15 @@ 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) |