lkml.org 
[lkml]   [2017]   [Mar]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.4 23/28] fscrypt: fix renaming and linking special files
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric Biggers <ebiggers@google.com>

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.

Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


---
fs/ext4/crypto_policy.c | 6 ++++++
fs/f2fs/crypto_policy.c | 5 +++++
2 files changed, 11 insertions(+)

--- a/fs/ext4/crypto_policy.c
+++ b/fs/ext4/crypto_policy.c
@@ -156,6 +156,12 @@ int ext4_is_child_context_consistent_wit
WARN_ON(1); /* Should never happen */
return 0;
}
+
+ /* 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 (!ext4_encrypted_inode(parent))
return 1;
--- a/fs/f2fs/crypto_policy.c
+++ b/fs/f2fs/crypto_policy.c
@@ -149,6 +149,11 @@ int f2fs_is_child_context_consistent_wit
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 (!f2fs_encrypted_inode(parent))
return 1;

\
 
 \ /
  Last update: 2017-03-20 18:52    [W:0.160 / U:0.144 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site