[123/289] ipc: initialize structure memory to zero for compat functions

Greg KH
2010-12-08T01:37:29Z

From: Dan Rosenberg <drosenberg@vsecurity.com>

commit 03145beb455cf5c20a761e8451e30b8a74ba58d9 upstream.

This takes care of leaking uninitialized kernel stack memory to
userspace from non-zeroed fields in structs in compat ipc functions.

Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
ipc/compat.c | 6 ++++++
ipc/compat_mq.c | 5 +++++
2 files changed, 11 insertions(+)

--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -241,6 +241,8 @@ long compat_sys_semctl(int first, int se
struct semid64_ds __user *up64;
int version = compat_ipc_parse_version(&third);

+ memset(&s64, 0, sizeof(s64));
+
if (!uptr)
return -EINVAL;
if (get_user(pad, (u32 __user *) uptr))
@@ -421,6 +423,8 @@ long compat_sys_msgctl(int first, int se
int version = compat_ipc_parse_version(&second);
void __user *p;

+ memset(&m64, 0, sizeof(m64));
+
switch (second & (~IPC_64)) {
case IPC_INFO:
case IPC_RMID:
@@ -594,6 +598,8 @@ long compat_sys_shmctl(int first, int se
int err, err2;
int version = compat_ipc_parse_version(&second);

+ memset(&s64, 0, sizeof(s64));
+
switch (second & (~IPC_64)) {
case IPC_RMID:
case SHM_LOCK:
--- a/ipc/compat_mq.c
+++ b/ipc/compat_mq.c
@@ -53,6 +53,9 @@ asmlinkage long compat_sys_mq_open(const
void __user *p = NULL;
if (u_attr && oflag & O_CREAT) {
struct mq_attr attr;
+
+ memset(&attr, 0, sizeof(attr));
+
p = compat_alloc_user_space(sizeof(attr));
if (get_compat_mq_attr(&attr, u_attr) ||
copy_to_user(p, &attr, sizeof(attr)))
@@ -127,6 +130,8 @@ asmlinkage long compat_sys_mq_getsetattr
struct mq_attr __user *p = compat_alloc_user_space(2 * sizeof(*p));
long ret;

+ memset(&mqstat, 0, sizeof(mqstat));
+
if (u_mqstat) {
if (get_compat_mq_attr(&mqstat, u_mqstat) ||
copy_to_user(p, &mqstat, sizeof(mqstat)))