[PATCH 4.9 074/240] misc: vmw_vmci: explicitly initialize vmci_notify_bm_set_msg struct

Greg Kroah-Hartman
2021-05-20T11:13:50Z

From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

commit 376565b9717c30cd58ad33860fa42697615fa2e4 upstream.

KMSAN complains that the vmci_use_ppn64() == false path in
vmci_dbell_register_notification_bitmap() left upper 32bits of
bitmap_set_msg.bitmap_ppn64 member uninitialized.

=====================================================
BUG: KMSAN: uninit-value in kmsan_check_memory+0xd/0x10
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc7+ #4
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
Call Trace:
dump_stack+0x21c/0x280
kmsan_report+0xfb/0x1e0
kmsan_internal_check_memory+0x484/0x520
kmsan_check_memory+0xd/0x10
iowrite8_rep+0x86/0x380
vmci_send_datagram+0x150/0x280
vmci_dbell_register_notification_bitmap+0x133/0x1e0
vmci_guest_probe_device+0xcab/0x1e70
pci_device_probe+0xab3/0xe70
really_probe+0xd16/0x24d0
driver_probe_device+0x29d/0x3a0
device_driver_attach+0x25a/0x490
__driver_attach+0x78c/0x840
bus_for_each_dev+0x210/0x340
driver_attach+0x89/0xb0
bus_add_driver+0x677/0xc40
driver_register+0x485/0x8e0
__pci_register_driver+0x1ff/0x350
vmci_guest_init+0x3e/0x41
vmci_drv_init+0x1d6/0x43f
do_one_initcall+0x39c/0x9a0
do_initcall_level+0x1d7/0x259
do_initcalls+0x127/0x1cb
do_basic_setup+0x33/0x36
kernel_init_freeable+0x29a/0x3ed
kernel_init+0x1f/0x840
ret_from_fork+0x1f/0x30

Local variable ----bitmap_set_msg@vmci_dbell_register_notification_bitmap created at:
vmci_dbell_register_notification_bitmap+0x50/0x1e0
vmci_dbell_register_notification_bitmap+0x50/0x1e0

Bytes 28-31 of 32 are uninitialized
Memory access of size 32 starts at ffff88810098f570
=====================================================

Fixes: 83e2ec765be03e8a ("VMCI: doorbell implementation.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/20210402121742.3917-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/misc/vmw_vmci/vmci_doorbell.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/misc/vmw_vmci/vmci_doorbell.c
+++ b/drivers/misc/vmw_vmci/vmci_doorbell.c
@@ -334,7 +334,7 @@ int vmci_dbell_host_context_notify(u32 s
bool vmci_dbell_register_notification_bitmap(u32 bitmap_ppn)
{
int result;
- struct vmci_notify_bm_set_msg bitmap_set_msg;
+ struct vmci_notify_bm_set_msg bitmap_set_msg = { };

bitmap_set_msg.hdr.dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
VMCI_SET_NOTIFY_BITMAP);