01/01: [NTOSKRNL] Fix a nullptr dereference in IopStartDevice

[Mark Jansen]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=b2b1c054e4dad11fe6775…

commit b2b1c054e4dad11fe6775d10f35d65c68422e3b4
Author:     Mark Jansen <mark.jansen(a)reactos.org>
AuthorDate: Sun Aug 5 22:14:44 2018 +0200
Commit:     Mark Jansen <mark.jansen(a)reactos.org>
CommitDate: Mon Aug 6 20:51:21 2018 +0200

    [NTOSKRNL] Fix a nullptr dereference in IopStartDevice
---
 ntoskrnl/io/pnpmgr/pnpmgr.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/ntoskrnl/io/pnpmgr/pnpmgr.c b/ntoskrnl/io/pnpmgr/pnpmgr.c
index 62ad7a253f..e4cb7db6d6 100644
--- a/ntoskrnl/io/pnpmgr/pnpmgr.c
+++ b/ntoskrnl/io/pnpmgr/pnpmgr.c
@@ -786,7 +786,7 @@ IopStartDevice(
 {
    NTSTATUS Status;
    HANDLE InstanceHandle = NULL, ControlHandle = NULL;
-   UNICODE_STRING KeyName;
+   UNICODE_STRING KeyName, ValueString;
    OBJECT_ATTRIBUTES ObjectAttributes;
 
    if (DeviceNode->Flags & DNF_DISABLED)
@@ -817,7 +817,10 @@ IopStartDevice(
        goto ByeBye;
 
    RtlInitUnicodeString(&KeyName, L"ActiveService");
-   Status = ZwSetValueKey(ControlHandle, &KeyName, 0, REG_SZ,
DeviceNode->ServiceName.Buffer, DeviceNode->ServiceName.Length +
sizeof(UNICODE_NULL));
+   ValueString = DeviceNode->ServiceName;
+   if (!ValueString.Buffer)
+       RtlInitUnicodeString(&ValueString, L"");
+   Status = ZwSetValueKey(ControlHandle, &KeyName, 0, REG_SZ, ValueString.Buffer,
ValueString.Length + sizeof(UNICODE_NULL));
    // }
 
 ByeBye: