This is a note to let you know that I've just added the patch titled
fscrypto: lock inode while 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-lock-inode-while-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 8906a8223ad4909b391c5628f7991ebceda30e52 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Sat, 15 Oct 2016 09:48:50 -0400
Subject: fscrypto: lock inode while setting encryption policy
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 8906a8223ad4909b391c5628f7991ebceda30e52 upstream.
i_rwsem needs to be acquired while setting an encryption policy so that
concurrent calls to FS_IOC_SET_ENCRYPTION_POLICY are correctly
serialized (especially the ->get_context() + ->set_context() pair), and
so that new files cannot be created in the directory during or after the
->empty_dir() check.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Reviewed-by: Richard Weinberger <richard@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/ioctl.c | 4 ++++
fs/f2fs/file.c | 9 ++++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -633,8 +633,12 @@ resizefs_out:
if (err)
goto encryption_policy_out;
+ mutex_lock(&inode->i_mutex);
+
err = ext4_process_policy(&policy, inode);
+ mutex_unlock(&inode->i_mutex);
+
mnt_drop_write_file(filp);
encryption_policy_out:
return err;
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1535,12 +1535,19 @@ static int f2fs_ioc_set_encryption_polic
#ifdef CONFIG_F2FS_FS_ENCRYPTION
struct f2fs_encryption_policy policy;
struct inode *inode = file_inode(filp);
+ int err;
if (copy_from_user(&policy, (struct f2fs_encryption_policy __user *)arg,
sizeof(policy)))
return -EFAULT;
- return f2fs_process_policy(&policy, inode);
+ mutex_lock(&inode->i_mutex);
+
+ err = f2fs_process_policy(&policy, inode);
+
+ mutex_unlock(&inode->i_mutex);
+
+ return err;
#else
return -EOPNOTSUPP;
#endif
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-4.4/fscrypto-lock-inode-while-setting-encryption-policy.patch
queue-4.4/fscrypt-fix-renaming-and-linking-special-files.patch