This is a note to let you know that I've just added the patch titled
fscrypto: add authorization check for setting encryption policy
to the 4.4-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:
fscrypto-add-authorization-check-for-setting-encryption-policy.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 163ae1c6ad6299b19e22b4a35d5ab24a89791a98 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Thu, 8 Sep 2016 10:57:08 -0700
Subject: fscrypto: add authorization check for setting encryption policy
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 163ae1c6ad6299b19e22b4a35d5ab24a89791a98 upstream.
On an ext4 or f2fs filesystem with file encryption supported, a user
could set an encryption policy on any empty directory(*) to which they
had readonly access. This is obviously problematic, since such a
directory might be owned by another user and the new encryption policy
would prevent that other user from creating files in their own directory
(for example).
Fix this by requiring inode_owner_or_capable() permission to set an
encryption policy. This means that either the caller must own the file,
or the caller must have the capability CAP_FOWNER.
(*) Or also on any regular file, for f2fs v4.6 and later and ext4
v4.8-rc1 and later; a separate bug fix is coming for that.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/crypto_policy.c | 3 +++
fs/f2fs/crypto_policy.c | 3 +++
2 files changed, 6 insertions(+)
--- a/fs/ext4/crypto_policy.c
+++ b/fs/ext4/crypto_policy.c
@@ -102,6 +102,9 @@ static int ext4_create_encryption_contex
int ext4_process_policy(const struct ext4_encryption_policy *policy,
struct inode *inode)
{
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
if (policy->version != 0)
return -EINVAL;
--- a/fs/f2fs/crypto_policy.c
+++ b/fs/f2fs/crypto_policy.c
@@ -89,6 +89,9 @@ static int f2fs_create_encryption_contex
int f2fs_process_policy(const struct f2fs_encryption_policy *policy,
struct inode *inode)
{
+ if (!inode_owner_or_capable(inode))
+ return -EACCES;
+
if (policy->version != 0)
return -EINVAL;
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-4.4/fscrypto-add-authorization-check-for-setting-encryption-policy.patch
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