Patch "fscrypt: fix renaming and linking special files" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

fscrypt: fix renaming and linking special files

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
fscrypt-fix-renaming-and-linking-special-files.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Eric Biggers <[email protected]>
Date: Mon, 19 Dec 2016 14:20:13 -0800
Subject: fscrypt: fix renaming and linking special files

From: Eric Biggers <[email protected]>

commit 42d97eb0ade31e1bc537d086842f5d6e766d9d51 upstream.

Attempting to link a device node, named pipe, or socket file into an encrypted directory through rename(2) or link(2) always failed with EPERM. This happened because fscrypt_has_permitted_context() saw that the file was unencrypted and forbid creating the link. This behavior was unexpected because such files are never encrypted; only regular files, directories, and symlinks can be encrypted.

To fix this, make fscrypt_has_permitted_context() always return true on special files.

This will be covered by a test in my encryption xfstests patchset.

---
 fs/crypto/policy.c |    5 +++++
 1 file changed, 5 insertions(+)

@@ -171,6 +171,11 @@ int fscrypt_has_permitted_context(struct
 		BUG_ON(1);
 	}
 
+	/* No restrictions on file types which are never encrypted */
+	if (!S_ISREG(child->i_mode) && !S_ISDIR(child->i_mode) &&
+	    !S_ISLNK(child->i_mode))
+		return 1;
+
 	/* no restrictions if the parent directory is not encrypted */
 	if (!parent->i_sb->s_cop->is_encrypted(parent))
 		return 1;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/fscrypt-fix-renaming-and-linking-special-files.patch