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authorTyler Hicks <tyhicks@canonical.com>2011-11-05 13:45:08 -0400
committerTyler Hicks <tyhicks@canonical.com>2012-02-16 16:06:21 -0600
commit4a26620df451ad46151ad21d711ed43e963c004e (patch)
treebf035ea6a656b3e19fe93bf37991632cad96d971 /fs/ecryptfs/keystore.c
parentc38e23456278e967f094b08247ffc3711b1029b2 (diff)
downloadlinux-4a26620df451ad46151ad21d711ed43e963c004e.tar.gz
eCryptfs: Improve statfs reporting
statfs() calls on eCryptfs files returned the wrong filesystem type and, when using filename encryption, the wrong maximum filename length. If mount-wide filename encryption is enabled, the cipher block size and the lower filesystem's max filename length will determine the max eCryptfs filename length. Pre-tested, known good lengths are used when the lower filesystem's namelen is 255 and a cipher with 8 or 16 byte block sizes is used. In other, less common cases, we fall back to a safe rounded-down estimate when determining the eCryptfs namelen. https://launchpad.net/bugs/885744 Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reported-by: Kees Cook <keescook@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: John Johansen <john.johansen@canonical.com>
Diffstat (limited to 'fs/ecryptfs/keystore.c')
-rw-r--r--fs/ecryptfs/keystore.c9
1 files changed, 3 insertions, 6 deletions
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 8e3b943e330f..2333203a120b 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -679,10 +679,7 @@ ecryptfs_write_tag_70_packet(char *dest, size_t *remaining_bytes,
* Octets N3-N4: Block-aligned encrypted filename
* - Consists of a minimum number of random characters, a \0
* separator, and then the filename */
- s->max_packet_size = (1 /* Tag 70 identifier */
- + 3 /* Max Tag 70 packet size */
- + ECRYPTFS_SIG_SIZE /* FNEK sig */
- + 1 /* Cipher identifier */
+ s->max_packet_size = (ECRYPTFS_TAG_70_MAX_METADATA_SIZE
+ s->block_aligned_filename_size);
if (dest == NULL) {
(*packet_size) = s->max_packet_size;
@@ -934,10 +931,10 @@ ecryptfs_parse_tag_70_packet(char **filename, size_t *filename_size,
goto out;
}
s->desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
- if (max_packet_size < (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1)) {
+ if (max_packet_size < ECRYPTFS_TAG_70_MIN_METADATA_SIZE) {
printk(KERN_WARNING "%s: max_packet_size is [%zd]; it must be "
"at least [%d]\n", __func__, max_packet_size,
- (1 + 1 + ECRYPTFS_SIG_SIZE + 1 + 1));
+ ECRYPTFS_TAG_70_MIN_METADATA_SIZE);
rc = -EINVAL;
goto out;
}