ecryptfs: Bugfix for error related to ecryptfs_hash_buckets
The function ecryptfs_uid_hash wrongly assumes that the
second parameter to hash_long() is the number of hash
buckets instead of the number of hash bits.
This patch fixes that and renames the variable
ecryptfs_hash_buckets to ecryptfs_hash_bits to make it
clearer.
Fixes: CVE-2010-2492
Signed-off-by: Andre Osterhues <aosterhues@escrypt.com>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/messaging.c b/fs/ecryptfs/messaging.c
index 2d8dbce..46c4dd8 100644
--- a/fs/ecryptfs/messaging.c
+++ b/fs/ecryptfs/messaging.c
@@ -31,9 +31,9 @@
static struct hlist_head *ecryptfs_daemon_hash;
struct mutex ecryptfs_daemon_hash_mux;
-static int ecryptfs_hash_buckets;
+static int ecryptfs_hash_bits;
#define ecryptfs_uid_hash(uid) \
- hash_long((unsigned long)uid, ecryptfs_hash_buckets)
+ hash_long((unsigned long)uid, ecryptfs_hash_bits)
static u32 ecryptfs_msg_counter;
static struct ecryptfs_msg_ctx *ecryptfs_msg_ctx_arr;
@@ -486,18 +486,19 @@
}
mutex_init(&ecryptfs_daemon_hash_mux);
mutex_lock(&ecryptfs_daemon_hash_mux);
- ecryptfs_hash_buckets = 1;
- while (ecryptfs_number_of_users >> ecryptfs_hash_buckets)
- ecryptfs_hash_buckets++;
+ ecryptfs_hash_bits = 1;
+ while (ecryptfs_number_of_users >> ecryptfs_hash_bits)
+ ecryptfs_hash_bits++;
ecryptfs_daemon_hash = kmalloc((sizeof(struct hlist_head)
- * ecryptfs_hash_buckets), GFP_KERNEL);
+ * (1 << ecryptfs_hash_bits)),
+ GFP_KERNEL);
if (!ecryptfs_daemon_hash) {
rc = -ENOMEM;
printk(KERN_ERR "%s: Failed to allocate memory\n", __func__);
mutex_unlock(&ecryptfs_daemon_hash_mux);
goto out;
}
- for (i = 0; i < ecryptfs_hash_buckets; i++)
+ for (i = 0; i < (1 << ecryptfs_hash_bits); i++)
INIT_HLIST_HEAD(&ecryptfs_daemon_hash[i]);
mutex_unlock(&ecryptfs_daemon_hash_mux);
ecryptfs_msg_ctx_arr = kmalloc((sizeof(struct ecryptfs_msg_ctx)
@@ -554,7 +555,7 @@
int i;
mutex_lock(&ecryptfs_daemon_hash_mux);
- for (i = 0; i < ecryptfs_hash_buckets; i++) {
+ for (i = 0; i < (1 << ecryptfs_hash_bits); i++) {
int rc;
hlist_for_each_entry(daemon, elem,