The MD5 TFM for an inode might be manipulated concurrently if two
separate reads on the same file occur. The crypt_stat struct for the
same inode may be manipulated concurrently if two open events on the
same inode occur. This patch adds mutex locks to resolve these issues.
Signed-off-by: Michael Halcrow <[email protected]>
---
fs/ecryptfs/crypto.c | 2 ++
fs/ecryptfs/file.c | 6 ++++++
2 files changed, 8 insertions(+), 0 deletions(-)
13663b8871df88686621ca9b701392235bf838c0
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index a7889cc..39d7ec0 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -97,6 +97,7 @@ static int ecryptfs_calculate_md5(char *
int rc = 0;
struct scatterlist sg;
+ mutex_lock(&crypt_stat->cs_md5_tfm_mutex);
sg_init_one(&sg, (u8 *)src, len);
if (!crypt_stat->md5_tfm) {
crypt_stat->md5_tfm =
@@ -111,6 +112,7 @@ static int ecryptfs_calculate_md5(char *
crypto_digest_init(crypt_stat->md5_tfm);
crypto_digest_update(crypt_stat->md5_tfm, &sg, 1);
crypto_digest_final(crypt_stat->md5_tfm, dst);
+ mutex_unlock(&crypt_stat->cs_md5_tfm_mutex);
out:
return rc;
}
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index c84e1d2..b707a99 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -232,12 +232,14 @@ static int ecryptfs_open(struct inode *i
}
lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ mutex_lock(&crypt_stat->cs_mutex);
if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED)) {
ecryptfs_printk(KERN_DEBUG, "Setting flags for stat...\n");
/* Policy code enabled in future release */
ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_POLICY_APPLIED);
ECRYPTFS_SET_FLAG(crypt_stat->flags, ECRYPTFS_ENCRYPTED);
}
+ mutex_unlock(&crypt_stat->cs_mutex);
/* This mntget & dget is undone via fput when the file is released */
dget(lower_dentry);
lower_flags = file->f_flags;
@@ -263,10 +265,12 @@ static int ecryptfs_open(struct inode *i
rc = 0;
goto out;
}
+ mutex_lock(&crypt_stat->cs_mutex);
if (i_size_read(lower_inode) == 0) {
ecryptfs_printk(KERN_EMERG, "Zero-length lower file; "
"ecryptfs_create() had a problem?\n");
rc = -ENOENT;
+ mutex_unlock(&crypt_stat->cs_mutex);
goto out_puts;
} else if (!ECRYPTFS_CHECK_FLAG(crypt_stat->flags,
ECRYPTFS_POLICY_APPLIED)
@@ -283,9 +287,11 @@ static int ecryptfs_open(struct inode *i
* as-is to userspace. For release 0.1, we are
* going to default to -EIO. */
rc = -EIO;
+ mutex_unlock(&crypt_stat->cs_mutex);
goto out_puts;
}
}
+ mutex_unlock(&crypt_stat->cs_mutex);
ecryptfs_printk(KERN_DEBUG, "inode w/ addr = [0x%p], i_ino = [0x%.16x] "
"size: [0x%.16x]\n", inode, inode->i_ino,
i_size_read(inode));
--
1.3.3
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