No subject

[Surbhi Palande]

SRU  Justification: 
Impact:  Bug in the Ecryptfs disallowed saving the file under the ecryptfs
directory ~/Private using Emacs.

Fix: The cherry picked patch from the upstream commit id
"b0105eaefa7cce8f4a941d0fc6354b250d30e745" fixed this bug. Previous to this
fix a cipher code was not recognized and as a result memory was not allocated
to some pointer. However this pointer was freed without allocation.
This fix, prevents the freeing of memory when it is not
recognised/allocated.

Testcase: The reporter of the bug, has verified that this patch has fixed this
bug for him.


>From d2504c185b312650445d95d2cfeac80309af237a Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks at linux.vnet.ibm.com>
Date: Tue, 11 Aug 2009 00:36:32 -0500
Subject: [PATCH] UBUNTU [Upstream]: eCryptfs: Handle unrecognized tag 3 cipher codes

BugLink: https://bugs.launchpad.net/415252

Returns an error when an unrecognized cipher code is present in a tag 3
packet or an ecryptfs_crypt_stat cannot be initialized.  Also sets an
crypt_stat->tfm error pointer to NULL to ensure that it will not be
incorrectly freed in ecryptfs_destroy_crypt_stat().

Acked-by: Serge Hallyn <serue at us.ibm.com>
Cc: ecryptfs-devel at lists.launchpad.net
Cc: stable <stable at kernel.org>
Signed-off-by: Tyler Hicks <tyhicks at linux.vnet.ibm.com>
(cherry picked from commit b0105eaefa7cce8f4a941d0fc6354b250d30e745)
Signed-off-by: Surbhi Palande <surbhi.palande at canonical.com>
---
 fs/ecryptfs/crypto.c   |    1 +
 fs/ecryptfs/keystore.c |   10 +++++++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 8b65f28..bbf080b 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -814,6 +814,7 @@ int ecryptfs_init_crypt_ctx(struct ecryptfs_crypt_stat *crypt_stat)
 	kfree(full_alg_name);
 	if (IS_ERR(crypt_stat->tfm)) {
 		rc = PTR_ERR(crypt_stat->tfm);
+		crypt_stat->tfm = NULL;
 		ecryptfs_printk(KERN_ERR, "cryptfs: init_crypt_ctx(): "
 				"Error initializing cipher [%s]\n",
 				crypt_stat->cipher);
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index 37bcb43..b41af15 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -1317,8 +1317,10 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
 		rc = -EINVAL;
 		goto out_free;
 	}
-	ecryptfs_cipher_code_to_string(crypt_stat->cipher,
-				       (u16)data[(*packet_size)]);
+	rc = ecryptfs_cipher_code_to_string(crypt_stat->cipher,
+					    (u16)data[(*packet_size)]);
+	if (rc)
+		goto out_free;
 	/* A little extra work to differentiate among the AES key
 	 * sizes; see RFC2440 */
 	switch(data[(*packet_size)++]) {
@@ -1329,7 +1331,9 @@ parse_tag_3_packet(struct ecryptfs_crypt_stat *crypt_stat,
 		crypt_stat->key_size =
 			(*new_auth_tok)->session_key.encrypted_key_size;
 	}
-	ecryptfs_init_crypt_ctx(crypt_stat);
+	rc = ecryptfs_init_crypt_ctx(crypt_stat);
+	if (rc)
+		goto out_free;
 	if (unlikely(data[(*packet_size)++] != 0x03)) {
 		printk(KERN_WARNING "Only S2K ID 3 is currently supported\n");
 		rc = -ENOSYS;
-- 
1.6.0.4