Proper cipher support isn't checked at mount time

[Tyler Hicks]

eCryptfs should check to see if we have the appropriate cipher code (as defined in RFC 2440) for a given cipher at mount time. We are currently waiting all the way until a write occurs to detect if we know of the proper cipher code.

To reproduce:
---
gentoo-virt mnt # mount -it ecryptfs /mnt/.ecryptfs-ext3 /mnt/ecryptfs-ext3/ -o \
ecryptfs_sig=7fa06f4b66fcde02,ecryptfs_cipher=camellia,ecryptfs_key_bytes=16,rw,noauto
gentoo-virt ecryptfs-ext3 # echo "camellia cipher test" > /mnt/ecryptfs-ext3/test
-bash: /mnt/ecryptfs-ext3/test: Invalid argument
---

Relevant log entries:
---
Mar 6 10:15:57 gentoo-virt kernel: write_tag_3_packet: Unable to generate code for cipher [camellia]
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_generate_key_packet_set: Error writing tag 3 packet
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_write_headers_virt: Error generating key packet set; rc = [-22]
Mar 6 10:15:57 gentoo-virt kernel: ecryptfs_write_metadata: Error whilst writing headers; rc = [-22]
Mar 6 10:15:57 gentoo-virt kernel: Error writing headers; rc = [-22]
---

[Tyler Hicks (tyhicks)]

Making this low importance, we don't handle it too bad currently, but it would be nice for the check to be done at mount time.

[Tim Sally (tsally)]

I recently posted a fix for this issue.

http://lkml.indiana.edu/hypermail/linux/kernel/1207.1/01526.html

https://github.com/tsally/ecryptfs-tsally/commit/24ce75267bf4129459290c5d2fdae8be2c37733f

Cheers,

Tim

[Tyler Hicks (tyhicks)]

Committed to the eCryptfs next branch. Thanks again, Tim!

[Tyler Hicks (tyhicks)]

This fix was merged into Linus' tree. It should be released in 3.6-rc1.

http://git.kernel.org/linus/5f5b331d5c21228a6519dcb793fc1629646c51a6

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.5.0-15.21

---------------
linux (3.5.0-15.21) quantal; urgency=low

  [ Tim Gardner ]

  * ubuntu: AUFS -- update to 18e455787597579fe144cdb2f18aa6a0a32c46a4
  * [Config] Enable aufs
    - LP: #908784

  [ Upstream Kernel Changes ]

  * eCryptfs: check for eCryptfs cipher support at mount
    - LP: #338914
  * drm/i915: pnv has a backlight polarity control bit, too
    - LP: #954661
  * drm/i915: clear up backlight #define confusion on gen4+
    - LP: #954661
  * drm/i915: properly enable the blc controller on the right pipe
    - LP: #954661
  * drm/i915: allow pipe A for lvds on gen4
    - LP: #954661
 -- Tim Gardner <email address hidden> Tue, 18 Sep 2012 08:37:51 -0400

[Colin Ian King (colin-king)]

Tested Lucid -proposed: Linux ubuntu 2.6.32-45-server #100-Ubuntu SMP Wed Nov 14 11:02:27 UTC 2012 x86_64 GNU/Linux

tested by:

1. mount using:
   mount -t ecryptfs /lower /upper
2. umount
3. add the mount password into the kernel keyring using ecryptfs-add-passphrase
4. try to remount using the sig from step 1 and the camellia cipher:

mount -it ecryptfs /lower /upper -o ecryptfs_sig=xxxxxxxxxxxxxxx,ecryptfs_cipher=camellia

without the fix /upper is mounted and then the kernel complains when we write a file to /upper. With the fix, the kernel does not mount (as expected) and the kernel error message appears:

[ 120.784003] ecryptfs_parse_options: eCryptfs doesn't support cipher: camellia

..so this passes the test for Lucid -proposed.

[Herton R. Krzesinski (herton)]

This bug is awaiting verification that the kernels for Oneiric (3.0.0-28.45) and Precise (3.2.0-34.53) in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed-<releasename>' to 'verification-done-<releasename>'.

If verification is not done by one week from today, this fix will be dropped from the source code, and this bug will be closed.

See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you!

[Colin Ian King (colin-king)]

Tested Oneiric -proposed: Linux ubuntu 3.0.0-28-server #45-Ubuntu SMP Wed Nov 14 22:15:34

Repeated the test (see comment #6). Without the fix /upper is mounted and then the kernel complains when we write a file to /upper. With the fix, the kernel does not mount (as expected) and the kernel error message appears:

[ 69.717985] ecryptfs_parse_options: eCryptfs: unrecognized option [ecyptfs_cipher=camellia]

..so this passes the test for Oneiric -proposed.

[Colin Ian King (colin-king)]

Tested Precise -proposed: Linux ubuntu 3.2.0-34-generic #53-Ubuntu SMP Thu Nov 15 10:48:16

Repeated the test (see comment #6). Without the fix /upper is mounted and then the kernel complains when we write a file to /upper. With the fix, the kernel does not mount (as expected) and the kernel error message appears:

[ 74.298508] ecryptfs_parse_options: eCryptfs doesn't support cipher: camellia

[Herton R. Krzesinski (herton)]

Thanks for the quick verification Colin. Oneiric is now free for testing, Precise still has some other SRUs to be verified.

[Adam Conrad (adconrad)]

The verification of this Stable Release Update has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regresssions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.0.0-28.45

---------------
linux (3.0.0-28.45) oneiric-proposed; urgency=low

  [Luis Henriques]

  * Release Tracking Bug
    - LP: #1078663

  [ Tim Gardner ]

  * [Config] updateconfigs for stable updates

  [ Upstream Kernel Changes ]

  * Revert "SUNRPC: Ensure we close the socket on EPIPE errors too..."
    - LP: #1075332
  * mn10300: only add -mmem-funcs to KBUILD_CFLAGS if gcc supports it
    - LP: #1067857
  * kbuild: make: fix if_changed when command contains backslashes
    - LP: #1067857
  * media: rc: ite-cir: Initialise ite_dev::rdev earlier
    - LP: #1067857
  * ACPI: run _OSC after ACPI_FULL_INITIALIZATION
    - LP: #1067857
  * PCI: acpiphp: check whether _ADR evaluation succeeded
    - LP: #1067857
  * lib/gcd.c: prevent possible div by 0
    - LP: #1067857
  * kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()
    - LP: #1067857
  * drivers/scsi/atp870u.c: fix bad use of udelay
    - LP: #1067857
  * workqueue: add missing smp_wmb() in process_one_work()
    - LP: #1067857
  * xfrm: Workaround incompatibility of ESN and async crypto
    - LP: #1067857
  * xfrm_user: return error pointer instead of NULL
    - LP: #1067857
  * xfrm_user: return error pointer instead of NULL #2
    - LP: #1067857
  * xfrm: fix a read lock imbalance in make_blackhole
    - LP: #1067857
  * xfrm_user: fix info leak in copy_to_user_auth()
    - LP: #1067857
  * xfrm_user: fix info leak in copy_to_user_state()
    - LP: #1067857
  * xfrm_user: fix info leak in copy_to_user_policy()
    - LP: #1067857
  * xfrm_user: fix info leak in copy_to_user_tmpl()
    - LP: #1067857
  * xfrm_user: don't copy esn replay window twice for new states
    - LP: #1067857
  * xfrm_user: ensure user supplied esn replay window is valid
    - LP: #1067857
  * net: ethernet: davinci_cpdma: decrease the desc count when cleaning up
    the remaining packets
    - LP: #1067857
  * ixp4xx_hss: fix build failure due to missing linux/module.h inclusion
    - LP: #1067857
  * netxen: check for root bus in netxen_mask_aer_correctable
    - LP: #1067857
  * net-sched: sch_cbq: avoid infinite loop
    - LP: #1067857
  * pkt_sched: fix virtual-start-time update in QFQ
    - LP: #1067857
  * sierra_net: Endianess bug fix.
    - LP: #1067857
  * 8021q: fix mac_len recomputation in vlan_untag()
    - LP: #1067857
  * ipv6: release reference of ip6_null_entry's dst entry in __ip6_del_rt
    - LP: #1067857
  * tcp: flush DMA queue before sk_wait_data if rcv_wnd is zero
    - LP: #1067857
  * sctp: Don't charge for data in sndbuf again when transmitting packet
    - LP: #1067857
  * pppoe: drop PPPOX_ZOMBIEs in pppoe_release
    - LP: #1067857
  * net: small bug on rxhash calculation
    - LP: #1067857
  * net: guard tcp_set_keepalive() to tcp sockets
    - LP: #1067857
  * ipv4: raw: fix icmp_filter()
    - LP: #1067857
  * ipv6: raw: fix icmpv6_filter()
    - LP: #1067857
  * ipv6: mip6: fix mip6_mh_filter()
    - LP: #1067857
  * l2tp: fix a typo in l2tp_eth_dev_recv()
    - LP: #1067857
  * netrom: copy_datagram_iovec can fail
    - LP: #1067857
  * net: do not disable sg for packets requiring no checksum
    - LP: #1067857
  * ...

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 2.6.32-45.100

---------------
linux (2.6.32-45.100) lucid-proposed; urgency=low

  [Luis Henriques]

  * Release Tracking Bug
    - LP: #1078385

  [ Upstream Kernel Changes ]

  * eCryptfs: check for eCryptfs cipher support at mount
    - LP: #338914
  * net: fix divide by zero in tcp algorithm illinois
    - LP: #1077091
    - CVE-2012-4565
 -- Luis Henriques <email address hidden> Tue, 13 Nov 2012 17:53:05 +0000

[Launchpad Janitor (janitor)]

This bug was fixed in the package linux - 3.2.0-34.53

---------------
linux (3.2.0-34.53) precise-proposed; urgency=low

  [Luis Henriques]

  * Release Tracking Bug
    - LP: #1078760

  [ Kamal Mostafa ]

  * SAUCE: input: Cypress PS/2 Trackpad list additional contributors

  [ Kyle Fazzari ]

  * SAUCE: input: Cypress PS/2 Trackpad fix multi-source, double-click
    - LP: #1055788
  * SAUCE: input: Cypress PS/2 Trackpad fix lost sync upon palm contact
    - LP: #1048258
  * SAUCE: input: Cypress PS/2 Trackpad fix taps turning into hardware
    clicks
    - LP: #1064086

  [ Tim Gardner ]

  * [Config] remove ndiswrapper from Provides:
    - LP: #1076395
  * [Config] CONFIG_HP_WATCHDOG=m for x86en
    - LP: #1076342

  [ Upstream Kernel Changes ]

  * Revert "SUNRPC: Ensure we close the socket on EPIPE errors too..."
    - LP: #1075355
  * Revert "ath9k_hw: Updated AR9003 tx gain table for 5GHz"
    - LP: #1075355
  * eCryptfs: check for eCryptfs cipher support at mount
    - LP: #338914
  * isci: fix isci_pci_probe() generates warning on efi failure path
    - LP: #1068162
  * mtd: nand: Use the mirror BBT descriptor when reading its version
    - LP: #1068162
  * drm/i915: prevent possible pin leak on error path
    - LP: #1068162
  * workqueue: add missing smp_wmb() in process_one_work()
    - LP: #1068162
  * TTY: ttyprintk, don't touch behind tty->write_buf
    - LP: #1068162
  * Remove BUG_ON from n_tty_read()
    - LP: #1068162
  * n_gsm.c: Implement 3GPP27.010 DLC start-up procedure in MUX
    - LP: #1068162
  * n_gsm: uplink SKBs accumulate on list
    - LP: #1068162
  * n_gsm : Flow control handling in Mux driver
    - LP: #1068162
  * char: n_gsm: remove message filtering for contipated DLCI
    - LP: #1068162
  * n_gsm: added interlocking for gsm_data_lock for certain code paths
    - LP: #1068162
  * n_gsm: avoid accessing freed memory during CMD_FCOFF condition
    - LP: #1068162
  * n_gsm: replace kfree_skb w/ appropriate dev_* versions
    - LP: #1068162
  * n_gsm: memory leak in uplink error path
    - LP: #1068162
  * UBI: fix autoresize handling in R/O mode
    - LP: #1068162
  * UBI: erase free PEB with bitflip in EC header
    - LP: #1068162
  * firmware: Add missing attributes to EFI variable attribute print out
    from sysfs
    - LP: #1068162
  * tools/hv: Fix exit() error code
    - LP: #1068162
  * slab: fix the DEADLOCK issue on l3 alien lock
    - LP: #1068162
  * gspca_pac7302: Add usb-id for 145f:013c
    - LP: #1068162
  * gspca_pac7302: add support for device 1ae7:2001 Speedlink Snappy
    Microphone SL-6825-SBK
    - LP: #1068162
  * xhci: Warn when hosts don't halt.
    - LP: #1068162
  * xHCI: add cmd_ring_state
    - LP: #1068162
  * xHCI: add aborting command ring function
    - LP: #1068162
  * xHCI: cancel command after command timeout
    - LP: #1068162
  * hpsa: Use LUN reset instead of target reset
    - LP: #1068162
  * rc: ite-cir: Initialise ite_dev::rdev earlier
    - LP: #1068162
  * staging: speakup_soft: Fix reading of init string
    - LP: #1068162
  * target: fix return code in target_core_init_configfs error path
    - LP: #1068162
  * powerpc/eeh: Lock module while handling EEH event
  ...