This is a note to let you know that I've just added the patch titled fscrypto: require write access to mount to set 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-require-write-access-to-mount-to-set-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 ba63f23d69a3a10e7e527a02702023da68ef8a6d Mon Sep 17 00:00:00 2001 From: Eric Biggers <ebiggers@xxxxxxxxxx> Date: Thu, 8 Sep 2016 14:20:38 -0700 Subject: fscrypto: require write access to mount to set encryption policy commit ba63f23d69a3a10e7e527a02702023da68ef8a6d upstream. [Please apply to 4.4-stable. Note: this was already backported, but only to ext4; it was missed that it should go to f2fs as well. This is needed to make xfstest generic/395 pass on f2fs.] Since setting an encryption policy requires writing metadata to the filesystem, it should be guarded by mnt_want_write/mnt_drop_write. Otherwise, a user could cause a write to a frozen or readonly filesystem. This was handled correctly by f2fs but not by ext4. Make fscrypt_process_policy() handle it rather than relying on the filesystem to get it right. Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Acked-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/f2fs/file.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1541,12 +1541,18 @@ static int f2fs_ioc_set_encryption_polic sizeof(policy))) return -EFAULT; + err = mnt_want_write_file(filp); + if (err) + return err; + mutex_lock(&inode->i_mutex); err = f2fs_process_policy(&policy, inode); mutex_unlock(&inode->i_mutex); + mnt_drop_write_file(filp); + return err; #else return -EOPNOTSUPP; Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are queue-4.4/keys-fix-race-between-updating-and-finding-a-negative-key.patch queue-4.4/fscrypto-require-write-access-to-mount-to-set-encryption-policy.patch queue-4.4/fs-cache-fix-dereference-of-null-user_key_payload.patch queue-4.4/lib-digsig-fix-dereference-of-null-user_key_payload.patch queue-4.4/fscrypt-fix-dereference-of-null-user_key_payload.patch queue-4.4/f2fs-crypto-add-missing-locking-for-keyring_key-access.patch queue-4.4/keys-encrypted-fix-dereference-of-null-user_key_payload.patch queue-4.4/f2fs-crypto-replace-some-bug_on-s-with-error-checks.patch queue-4.4/keys-don-t-let-add_key-update-an-uninstantiated-key.patch