Commit 68924d2d authored May 27, 2016 by Eric W. Biederman Committed by Sasha Levin Jun 19, 2016

mnt: fs_fully_visible test the proper mount for MNT_LOCKED



[ Upstream commit d71ed6c930ac7d8f88f3cef6624a7e826392d61f ]

MNT_LOCKED implies on a child mount implies the child is locked to the
parent.  So while looping through the children the children should be
tested (not their parent).

Typically an unshare of a mount namespace locks all mounts together
making both the parent and the slave as locked but there are a few
corner cases where other things work.

Cc: stable@vger.kernel.org
Fixes: ceeb0e5d39fc ("vfs: Ignore unlocked mounts in fs_fully_visible")
Reported-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 7fca8723

fs/namespace.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3175,7 +3175,7 @@ static bool fs_fully_visible(struct file_system_type type, int new_mnt_flags)
		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))
		if (!(child->mnt.mnt_flags & MNT_LOCKED))
		continue;
		if (!S_ISDIR(inode->i_mode))
		goto next;