From: Colin Ian King <colin.king@canonical.com>

BugLink: http://bugs.launchpad.net/bugs/944990

SRU justification:

Impact:

From mhalcrow's original commit message:

Characters with ASCII values greater than the size of
filename_rev_map[] are valid filename characters.
ecryptfs_decode_from_filename() will access kernel memory beyond
that array, and ecryptfs_parse_tag_70_packet() will then decrypt
those characters. The attacker, using the FNEK of the crafted file,
can then re-encrypt the characters to reveal the kernel memory past
the end of the filename_rev_map[] array. I expect low security
impact since this array is statically allocated in the text area,
and the amount of memory past the array that is accessible is
limited by the largest possible ASCII filename character.

Fix:

Upstream commit 0f751e641a71157aa584c2a2e22fda52b52b8a56

Note: This patch has already been picked up in Lucid as part of
the stable updates process, but got overlooked for Natty.

Tyler Hicks (1):
eCryptfs: Extend array bounds for all filename chars

fs/ecryptfs/crypto.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

--
1.7.9


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