From 03145beb455cf5c20a761e8451e30b8a74ba58d9 Mon Sep 17 00:00:00 2001 From: Dan Rosenberg Date: Wed, 27 Oct 2010 15:34:17 -0700 Subject: [PATCH] ipc: initialize structure memory to zero for compat functions 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 Cc: Manfred Spraul Cc: Arnd Bergmann Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/compat.c | 6 ++++++ ipc/compat_mq.c | 5 +++++ 2 files changed, 11 insertions(+) diff --git a/ipc/compat.c b/ipc/compat.c index 9dc2c7d3c9e6..845a28738d3a 100644 --- a/ipc/compat.c +++ b/ipc/compat.c @@ -241,6 +241,8 @@ long compat_sys_semctl(int first, int second, int third, void __user *uptr) 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 second, void __user *uptr) 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 second, void __user *uptr) 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: diff --git a/ipc/compat_mq.c b/ipc/compat_mq.c index d8d1e9ff4e88..380ea4fe08e7 100644 --- a/ipc/compat_mq.c +++ b/ipc/compat_mq.c @@ -53,6 +53,9 @@ asmlinkage long compat_sys_mq_open(const char __user *u_name, 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(mqd_t mqdes, 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))) -- 2.20.1