[reactos] 02/04: [NTOS:PNP] Avoid an unnecessary stack buffer in EnumerateDevices. CORE-15882
https://git.reactos.org/?p=reactos.git;a=commitdiff;h=1b0fe76d0d06f49428730e...
commit 1b0fe76d0d06f49428730e8a0e8f41a4b4d6d3f3 Author: Thomas Faber thomas.faber@reactos.org AuthorDate: Sat May 2 17:33:24 2020 +0200 Commit: Thomas Faber thomas.faber@reactos.org CommitDate: Sun May 17 20:56:16 2020 +0200
[NTOS:PNP] Avoid an unnecessary stack buffer in EnumerateDevices. CORE-15882 --- ntoskrnl/io/pnpmgr/pnproot.c | 45 +++++++++++++++++++++++++++++--------------- 1 file changed, 30 insertions(+), 15 deletions(-)
diff --git a/ntoskrnl/io/pnpmgr/pnproot.c b/ntoskrnl/io/pnpmgr/pnproot.c index 46c78366282..5e2ec7473a0 100644 --- a/ntoskrnl/io/pnpmgr/pnproot.c +++ b/ntoskrnl/io/pnpmgr/pnproot.c @@ -439,7 +439,7 @@ static NTSTATUS CreateDeviceFromRegistry( _Inout_ PPNPROOT_FDO_DEVICE_EXTENSION DeviceExtension, - _In_ PCWSTR DevicePath, + _Inout_ PUNICODE_STRING DevicePath, _In_ PCWSTR InstanceId, _In_ HANDLE SubKeyHandle) { @@ -450,7 +450,8 @@ CreateDeviceFromRegistry( BUFFER Buffer1, Buffer2;
/* If the device already exists, there's nothing to do */ - Status = LocateChildDevice(DeviceExtension, DevicePath, InstanceId, &Device); + NT_ASSERT(DevicePath->Buffer[DevicePath->Length / sizeof(WCHAR)] == UNICODE_NULL); + Status = LocateChildDevice(DeviceExtension, DevicePath->Buffer, InstanceId, &Device); if (Status != STATUS_NO_SUCH_DEVICE) { return STATUS_SUCCESS; @@ -467,13 +468,8 @@ CreateDeviceFromRegistry( RtlZeroMemory(Device, sizeof(PNPROOT_DEVICE));
/* Fill device ID and instance ID */ - if (!RtlCreateUnicodeString(&Device->DeviceID, DevicePath)) - { - DPRINT1("RtlCreateUnicodeString() failed\n"); - Status = STATUS_NO_MEMORY; - goto cleanup; - } - + Device->DeviceID = *DevicePath; + RtlInitEmptyUnicodeString(DevicePath, NULL, 0); if (!RtlCreateUnicodeString(&Device->InstanceID, InstanceId)) { DPRINT1("RtlCreateUnicodeString() failed\n"); @@ -526,7 +522,7 @@ CreateDeviceFromRegistry( NULL))) { /* Non-fatal error */ - DPRINT1("Failed to read the LogConf key for %S\%S\n", DevicePath, InstanceId); + DPRINT1("Failed to read the LogConf key for %wZ\%S\n", &Device->DeviceID, InstanceId); }
/* Insert the newly created device into the list */ @@ -559,7 +555,7 @@ EnumerateDevices( UNICODE_STRING LegacyU = RTL_CONSTANT_STRING(L"LEGACY_"); UNICODE_STRING KeyName = RTL_CONSTANT_STRING(L"\Registry\Machine\" REGSTR_PATH_SYSTEMENUM L"\" REGSTR_KEY_ROOTENUM); UNICODE_STRING SubKeyName; - WCHAR DevicePath[MAX_PATH + 1]; + UNICODE_STRING DevicePath; HANDLE KeyHandle = NULL; HANDLE SubKeyHandle = NULL; ULONG KeyInfoSize, SubKeyInfoSize; @@ -705,13 +701,32 @@ EnumerateDevices( /* Terminate the string */ SubKeyInfo->Name[SubKeyInfo->NameLength / sizeof(WCHAR)] = 0;
- _snwprintf(DevicePath, sizeof(DevicePath) / sizeof(WCHAR), - L"%s\%s", REGSTR_KEY_ROOTENUM, KeyInfo->Name); - DPRINT("Found device %S\%S!\n", DevicePath, SubKeyInfo->Name); + /* Compute device ID */ + DevicePath.Length = 0; + DevicePath.MaximumLength = sizeof(REGSTR_KEY_ROOTENUM) + sizeof(L'\') + SubKeyName.Length; + DevicePath.Buffer = ExAllocatePoolWithTag(PagedPool, + DevicePath.MaximumLength, + TAG_PNP_ROOT); + if (DevicePath.Buffer == NULL) + { + DPRINT1("ExAllocatePoolWithTag() failed\n"); + Status = STATUS_NO_MEMORY; + goto cleanup; + } + + RtlAppendUnicodeToString(&DevicePath, REGSTR_KEY_ROOTENUM L"\"); + RtlAppendUnicodeStringToString(&DevicePath, &SubKeyName); + DPRINT("Found device %wZ\%S!\n", &DevicePath, SubKeyInfo->Name); Status = CreateDeviceFromRegistry(DeviceExtension, - DevicePath, + &DevicePath, SubKeyInfo->Name, SubKeyHandle); + + /* If CreateDeviceFromRegistry didn't take ownership and zero this, + * we need to free it + */ + RtlFreeUnicodeString(&DevicePath); + if (!NT_SUCCESS(Status)) { goto cleanup;
-
Thomas Faber