diff options
| author | Eric Dong <eric.dong@intel.com> | 2016-10-12 20:32:16 +0800 |
|---|---|---|
| committer | Ruiyu Ni <ruiyu.ni@intel.com> | 2016-10-19 10:20:04 +0800 |
| commit | e9fb71b29965aff2bf9e9caa1837ddcd069f2a27 (patch) | |
| tree | 94286d7c5640dc4a22dccc18804d1e52eeb37d67 | |
| parent | 67e11e4d5902dc77fc64876da5b71122bf128837 (diff) | |
| download | edk2-platforms-e9fb71b29965aff2bf9e9caa1837ddcd069f2a27.tar.xz | |
MdePkg UefiDevicePathLib: Validate buffer length before use buffer.
In IsDevicePathValid API, code should validate the device path
buffer not exceed the input MaxSize before reference the path
info.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
| -rw-r--r-- | MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c b/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c index 7f21a60380..82419a4e1b 100644 --- a/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c +++ b/MdePkg/Library/UefiDevicePathLib/DevicePathUtilities.c @@ -8,7 +8,7 @@ environment varibles. Multi-instance device paths should never be placed
on a Handle.
- Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+ Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@@ -61,25 +61,35 @@ IsDevicePathValid ( ASSERT (DevicePath != NULL);
- for (Count = 0, Size = 0; !IsDevicePathEnd (DevicePath); DevicePath = NextDevicePathNode (DevicePath)) {
+ if (MaxSize == 0){
+ MaxSize = MAX_UINTN;
+ }
+
+ Size = 0;
+ Count = 0;
+
+ while (MaxSize >= sizeof (EFI_DEVICE_PATH_PROTOCOL) &&
+ (MaxSize - sizeof (EFI_DEVICE_PATH_PROTOCOL) >= Size) &&
+ !IsDevicePathEnd (DevicePath)) {
NodeLength = DevicePathNodeLength (DevicePath);
if (NodeLength < sizeof (EFI_DEVICE_PATH_PROTOCOL)) {
return FALSE;
}
- if (MaxSize > 0) {
- Size += NodeLength;
- if (Size + END_DEVICE_PATH_LENGTH > MaxSize) {
- return FALSE;
- }
+ if (NodeLength > MAX_UINTN - Size) {
+ return FALSE;
}
+ Size += NodeLength;
+
if (PcdGet32 (PcdMaximumDevicePathNodeCount) > 0) {
Count++;
if (Count >= PcdGet32 (PcdMaximumDevicePathNodeCount)) {
return FALSE;
}
}
+
+ DevicePath = NextDevicePathNode (DevicePath);
}
//
@@ -88,6 +98,7 @@ IsDevicePathValid ( return (BOOLEAN) (DevicePathNodeLength (DevicePath) == END_DEVICE_PATH_LENGTH);
}
+
/**
Returns the Type field of a device path node.
|