[PATCH 5.5 249/399] visorbus: fix uninitialized variable access

Greg Kroah-Hartman
2020-02-21T08:42:58Z

From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit caf82f727e69b647f09d57a1fc56e69d22a5f483 ]

The setup_crash_devices_work_queue function only partially initializes
the message it sends to chipset_init, leading to undefined behavior:

drivers/visorbus/visorchipset.c: In function 'setup_crash_devices_work_queue':
drivers/visorbus/visorchipset.c:333:6: error: '((unsigned char*)&msg.hdr.flags)[0]' is used uninitialized in this function [-Werror=uninitialized]
if (inmsg->hdr.flags.response_expected)

Set up the entire structure, zero-initializing the 'response_expected'
flag.

This was apparently found by the patch that added the -O3 build option
in Kconfig.

Fixes: 12e364b9f08a ("staging: visorchipset driver to provide registration and other services")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20200107202950.782951-1-arnd@arndb.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/visorbus/visorchipset.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/visorbus/visorchipset.c b/drivers/visorbus/visorchipset.c
index ca752b8f495fa..cb1eb7e05f871 100644
--- a/drivers/visorbus/visorchipset.c
+++ b/drivers/visorbus/visorchipset.c
@@ -1210,14 +1210,17 @@ static void setup_crash_devices_work_queue(struct work_struct *work)
{
struct controlvm_message local_crash_bus_msg;
struct controlvm_message local_crash_dev_msg;
- struct controlvm_message msg;
+ struct controlvm_message msg = {
+ .hdr.id = CONTROLVM_CHIPSET_INIT,
+ .cmd.init_chipset = {
+ .bus_count = 23,
+ .switch_count = 0,
+ },
+ };
u32 local_crash_msg_offset;
u16 local_crash_msg_count;

/* send init chipset msg */
- msg.hdr.id = CONTROLVM_CHIPSET_INIT;
- msg.cmd.init_chipset.bus_count = 23;
- msg.cmd.init_chipset.switch_count = 0;
chipset_init(&msg);
/* get saved message count */
if (visorchannel_read(chipset_dev->controlvm_channel,
--
2.20.1