Description of problem:

When creating a new file in ecryptfs filesystem there's a invalid packet format reported by ecryptfs miscdev code. Input/output error is reported by kernel. 
When data is written to the new file this data is lost because of that error. When data is written to an existing file the problem does not occur.

Here's a console session capture of the problem:

[root@intel-d3c69-01 ~]# ecryptfs-manager 

eCryptfs key management menu
-------------------------------
	1. Add passphrase key to keyring
	2. Add public key to keyring
	3. Generate new public/private keypair
	4. Exit

Make selection: 3
Select key type to use for newly created files: 
 1) openssl
Selection: 1
SSL key file path [/root/.ecryptfs/pki/openssl/key.pem]: 
Passphrase: 
Returning to main menu

eCryptfs key management menu
-------------------------------
	1. Add passphrase key to keyring
	2. Add public key to keyring
	3. Generate new public/private keypair
	4. Exit

Make selection: 4
[root@intel-d3c69-01 ~]# mkdir .secret
[root@intel-d3c69-01 ~]# pgrep ecryptfsd
17575
[root@intel-d3c69-01 ~]# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
/root/.secret on /root/.secret type ecryptfs (rw,ecryptfs_sig=8431864ec283561b,ecryptfs_cipher=aes,ecryptfs_key_bytes=16,)
[root@intel-d3c69-01 ~]# umount .secret/
[root@intel-d3c69-01 ~]# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
[root@intel-d3c69-01 ~]# mount -t ecryptfs .secret/ .secret/
Select key type to use for newly created files: 
 1) passphrase
 2) openssl
Selection: 2
PEM key file [/root/.ecryptfs/pki/openssl/key.pem]: 
Method of providing the passphrase: 
 1) openssl_passwd: Enter on Console
 2) openssl_passwd_file: File Containing Passphrase
 3) openssl_passwd_fd: File Descriptor for File Containing Passphrase
Selection [openssl_passwd]: 1
Passphrase: 
Select cipher: 
 1) aes: blocksize = 16; min keysize = 16; max keysize = 32 (loaded)
 2) blowfish: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
 3) des3_ede: blocksize = 8; min keysize = 24; max keysize = 24 (not loaded)
 4) twofish: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
 5) cast6: blocksize = 16; min keysize = 16; max keysize = 32 (not loaded)
 6) cast5: blocksize = 8; min keysize = 5; max keysize = 16 (not loaded)
Selection [aes]: 1
Select key bytes: 
 1) 16
 2) 32
 3) 24
Selection [16]: 
Enable plaintext passthrough (y/n) [n]: n
Attempting to mount with the following options:
  ecryptfs_key_bytes=16
  ecryptfs_cipher=aes
  ecryptfs_sig=8431864ec283561b
WARNING: Based on the contents of [/root/.ecryptfs/sig-cache.txt],
it looks like you have never mounted with this key 
before. This could mean that you have typed your 
passphrase wrong.

Would you like to proceed with the mount (yes/no)? yes
Would you like to append sig [8431864ec283561b] to
[/root/.ecryptfs/sig-cache.txt] 
in order to avoid this warning in the future (yes/no)? no
Not adding sig to user sig cache file; continuing with mount.
Mounted eCryptfs
[root@intel-d3c69-01 ~]# 
[root@intel-d3c69-01 ~]# echo "secret" > .secret/file2
-bash: .secret/file2: Input/output error

(and output on console says:)
ecryptfs_miscdev_write: (1 + packet_size_length([1]) + packet_size([0]))([2]) != count([146]). Invalid packet format.
pki_encrypt_session_key: Failed to receive tag 67 packet from the user space daemon
Failed to encrypt session key via a key module; rc = [-5]
ecryptfs_generate_key_packet_set: Error writing tag 1 packet
ecryptfs_write_headers_virt: Error generating key packet set; rc = [-5]
ecryptfs_write_metadata: Error whilst writing headers; rc = [-5]
Error writing headers; rc = [-5]

however we're able to do following:

[root@intel-d3c69-01 ~]# cat .secret/file2 (the file is empty!)
[root@intel-d3c69-01 ~]# echo "blah" > .secret/file2 
[root@intel-d3c69-01 ~]# cat .secret/file2
blah
[root@intel-d3c69-01 ~]#


Version-Release number of selected component (if applicable):
Installed nightly RHEL5 Server tree RHEL5.3-Server-20081015.nightly
kernel-2.6.18-119.el5
ecryptfs-utils-56-4.el5


How reproducible:
100%
Create openssl key, mount ecryptfs filesystem over ext3 using this key, create file in new filesystem by echoing some data into it (the file must not exist!).

Steps to Reproduce:
(do following steps as root, using underlying ext3 filesystem, install ecryptfs-utils before)

1. use ecryptfs-manager to create new openssl key (use default values)
2. cd ~; mkdir .secret
3. pgrep ecryptfsd; [ $? -eq 1 ] && ecryptfsd
4. mount -t ecryptfs .secret .secret
5. rm -f .secret/file
6. echo "blah" > .secret/echoed_file
7. cat .secret/echoed_file
8. grep ecryptfs /var/log/messages (search for "Invalid packet format" string)

Actual results:
Data we want to write into the file on file creation is lost!

And in /var/log/messages I can see:

ecryptfs_miscdev_write: (1 + packet_size_length([1]) + packet_size([0]))([2]) != count([146]). Invalid packet format.
pki_encrypt_session_key: Failed to receive tag 67 packet from the user space daemon
Failed to encrypt session key via a key module; rc = [-5]
ecryptfs_generate_key_packet_set: Error writing tag 1 packet
ecryptfs_write_headers_virt: Error generating key packet set; rc = [-5]
ecryptfs_write_metadata: Error whilst writing headers; rc = [-5]
Error writing headers; rc = [-5]

Expected results:
Data is written into the file on file creation. No error is reported.

Additional info: