[PATCH 4.9 075/240] misc: vmw_vmci: explicitly initialize vmci_datagram payload

Greg Kroah-Hartman
2021-05-20T11:13:51Z

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

commit b2192cfeba8481224da0a4ec3b4a7ccd80b1623b upstream.

KMSAN complains that vmci_check_host_caps() left the payload part of
check_msg uninitialized.

=====================================================
BUG: KMSAN: uninit-value in kmsan_check_memory+0xd/0x10
CPU: 1 PID: 1 Comm: swapper/0 Tainted: G B 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+0x202/0x520
kmsan_check_memory+0xd/0x10
iowrite8_rep+0x86/0x380
vmci_guest_probe_device+0xf0b/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

Uninit was created at:
kmsan_internal_poison_shadow+0x5c/0xf0
kmsan_slab_alloc+0x8d/0xe0
kmem_cache_alloc+0x84f/0xe30
vmci_guest_probe_device+0xd11/0x1e70
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

Bytes 28-31 of 36 are uninitialized
Memory access of size 36 starts at ffff8881675e5f00
=====================================================

Fixes: 1f166439917b69d3 ("VMCI: guest side driver implementation.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/20210402121742.3917-2-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/misc/vmw_vmci/vmci_guest.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -172,7 +172,7 @@ static int vmci_check_host_caps(struct p
VMCI_UTIL_NUM_RESOURCES * sizeof(u32);
struct vmci_datagram *check_msg;

- check_msg = kmalloc(msg_size, GFP_KERNEL);
+ check_msg = kzalloc(msg_size, GFP_KERNEL);
if (!check_msg) {
dev_err(&pdev->dev, "%s: Insufficient memory\n", __func__);
return -ENOMEM;