patch "misc: vmw_vmci: explicitly initialize vmci_datagram payload" added to char-misc-testing

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    misc: vmw_vmci: explicitly initialize vmci_datagram payload

to my char-misc git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the char-misc-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


From b2192cfeba8481224da0a4ec3b4a7ccd80b1623b Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Fri, 2 Apr 2021 21:17:42 +0900
Subject: misc: vmw_vmci: explicitly initialize vmci_datagram payload

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(-)

diff --git a/drivers/misc/vmw_vmci/vmci_guest.c b/drivers/misc/vmw_vmci/vmci_guest.c
index cc8eeb361fcd..1018dc77269d 100644
--- a/drivers/misc/vmw_vmci/vmci_guest.c
+++ b/drivers/misc/vmw_vmci/vmci_guest.c
@@ -168,7 +168,7 @@ static int vmci_check_host_caps(struct pci_dev *pdev)
 				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;
-- 
2.31.1