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From 865ba07a0fd4fbc7a8203482411aacca3bbfbb9f Mon Sep 17 00:00:00 2001
From: akallabeth <akallabeth@posteo.net>
Date: Mon, 24 Oct 2022 10:41:55 +0200
Subject: [PATCH] Fixed path validation in drive channel
Check that canonical path is a subpath of the shared directory
(cherry picked from commit 844c94e6d0438fa7bd8ff8d5513c3f69c3018b85)
---
channels/drive/client/drive_file.c | 106 ++++++++++++++++++-----------
channels/drive/client/drive_file.h | 8 +--
channels/drive/client/drive_main.c | 8 +--
3 files changed, 73 insertions(+), 49 deletions(-)
diff --git a/channels/drive/client/drive_file.c b/channels/drive/client/drive_file.c
index 305438593..1ea4ab9da 100644
--- a/channels/drive/client/drive_file.c
+++ b/channels/drive/client/drive_file.c
@@ -34,6 +34,7 @@
#include <stdlib.h>
#include <string.h>
#include <time.h>
+#include <assert.h>
#include <winpr/wtypes.h>
#include <winpr/crt.h>
@@ -61,10 +62,14 @@
} while (0)
#endif
-static void drive_file_fix_path(WCHAR* path)
+static BOOL drive_file_fix_path(WCHAR* path, size_t length)
{
size_t i;
- size_t length = _wcslen(path);
+
+ if ((length == 0) || (length > UINT32_MAX))
+ return FALSE;
+
+ assert(path);
for (i = 0; i < length; i++)
{
@@ -75,58 +79,82 @@ static void drive_file_fix_path(WCHAR* path)
#ifdef WIN32
if ((length == 3) && (path[1] == L':') && (path[2] == L'/'))
- return;
+ return FALSE;
#else
if ((length == 1) && (path[0] == L'/'))
- return;
+ return FALSE;
#endif
if ((length > 0) && (path[length - 1] == L'/'))
path[length - 1] = L'\0';
+
+ return TRUE;
}
static WCHAR* drive_file_combine_fullpath(const WCHAR* base_path, const WCHAR* path,
- size_t PathLength)
+ size_t PathWCharLength)
{
- WCHAR* fullpath;
- size_t base_path_length;
+ BOOL ok = FALSE;
+ WCHAR* fullpath = NULL;
+ size_t length;
- if (!base_path || (!path && (PathLength > 0)))
- return NULL;
+ if (!base_path || (!path && (PathWCharLength > 0)))
+ goto fail;
- base_path_length = _wcslen(base_path) * 2;
- fullpath = (WCHAR*)calloc(1, base_path_length + PathLength + sizeof(WCHAR));
+ const size_t base_path_length = _wcsnlen(base_path, MAX_PATH);
+ length = base_path_length + PathWCharLength + 1;
+ fullpath = (WCHAR*)calloc(length, sizeof(WCHAR));
if (!fullpath)
+ goto fail;
+
+ CopyMemory(fullpath, base_path, base_path_length * sizeof(WCHAR));
+ if (path)
+ CopyMemory(&fullpath[base_path_length], path, PathWCharLength * sizeof(WCHAR));
+
+ if (!drive_file_fix_path(fullpath, length))
+ goto fail;
+
+ /* Ensure the path does not contain sequences like '..' */
+ const WCHAR dotdot[] = { '.', '.', '\0' };
+ if (_wcsstr(&fullpath[base_path_length], dotdot))
{
- WLog_ERR(TAG, "malloc failed!");
- return NULL;
+ char abuffer[MAX_PATH] = { 0 };
+ ConvertFromUnicode(CP_UTF8, 0, &fullpath[base_path_length], -1, (char**)&abuffer,
+ ARRAYSIZE(abuffer) - 1, NULL, NULL);
+
+ WLog_WARN(TAG, "[rdpdr] received invalid file path '%s' from server, aborting!",
+ &abuffer[base_path_length]);
+ goto fail;
}
- CopyMemory(fullpath, base_path, base_path_length);
- if (path)
- CopyMemory((char*)fullpath + base_path_length, path, PathLength);
- drive_file_fix_path(fullpath);
+ ok = TRUE;
+fail:
+ if (!ok)
+ {
+ free(fullpath);
+ fullpath = NULL;
+ }
return fullpath;
}
static BOOL drive_file_remove_dir(const WCHAR* path)
{
- WIN32_FIND_DATAW findFileData;
+ WIN32_FIND_DATAW findFileData = { 0 };
BOOL ret = TRUE;
- HANDLE dir;
- WCHAR* fullpath;
- WCHAR* path_slash;
- size_t base_path_length;
+ HANDLE dir = INVALID_HANDLE_VALUE;
+ WCHAR* fullpath = NULL;
+ WCHAR* path_slash = NULL;
+ size_t base_path_length = 0;
if (!path)
return FALSE;
- base_path_length = _wcslen(path) * 2;
- path_slash = (WCHAR*)calloc(1, base_path_length + sizeof(WCHAR) * 3);
+ base_path_length = _wcslen(path);
+ path_slash = (WCHAR*)calloc(base_path_length + 3, sizeof(WCHAR));
if (!path_slash)
{
@@ -134,12 +162,11 @@ static BOOL drive_file_remove_dir(const WCHAR* path)
return FALSE;
}
- CopyMemory(path_slash, path, base_path_length);
- path_slash[base_path_length / 2] = L'/';
- path_slash[base_path_length / 2 + 1] = L'*';
+ CopyMemory(path_slash, path, base_path_length * sizeof(WCHAR));
+ path_slash[base_path_length] = L'/';
+ path_slash[base_path_length + 1] = L'*';
DEBUG_WSTR("Search in %s", path_slash);
dir = FindFirstFileW(path_slash, &findFileData);
- path_slash[base_path_length / 2 + 1] = 0;
if (dir == INVALID_HANDLE_VALUE)
{
@@ -149,7 +176,7 @@ static BOOL drive_file_remove_dir(const WCHAR* path)
do
{
- size_t len = _wcslen(findFileData.cFileName);
+ const size_t len = _wcsnlen(findFileData.cFileName, ARRAYSIZE(findFileData.cFileName));
if ((len == 1 && findFileData.cFileName[0] == L'.') ||
(len == 2 && findFileData.cFileName[0] == L'.' && findFileData.cFileName[1] == L'.'))
@@ -157,7 +184,7 @@ static BOOL drive_file_remove_dir(const WCHAR* path)
continue;
}
- fullpath = drive_file_combine_fullpath(path_slash, findFileData.cFileName, len * 2);
+ fullpath = drive_file_combine_fullpath(path_slash, findFileData.cFileName, len);
DEBUG_WSTR("Delete %s", fullpath);
if (findFileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
@@ -333,13 +360,13 @@ static BOOL drive_file_init(DRIVE_FILE* file)
return file->file_handle != INVALID_HANDLE_VALUE;
}
-DRIVE_FILE* drive_file_new(const WCHAR* base_path, const WCHAR* path, UINT32 PathLength, UINT32 id,
- UINT32 DesiredAccess, UINT32 CreateDisposition, UINT32 CreateOptions,
- UINT32 FileAttributes, UINT32 SharedAccess)
+DRIVE_FILE* drive_file_new(const WCHAR* base_path, const WCHAR* path, UINT32 PathWCharLength,
+ UINT32 id, UINT32 DesiredAccess, UINT32 CreateDisposition,
+ UINT32 CreateOptions, UINT32 FileAttributes, UINT32 SharedAccess)
{
DRIVE_FILE* file;
- if (!base_path || (!path && (PathLength > 0)))
+ if (!base_path || (!path && (PathWCharLength > 0)))
return NULL;
file = (DRIVE_FILE*)calloc(1, sizeof(DRIVE_FILE));
@@ -359,7 +386,7 @@ DRIVE_FILE* drive_file_new(const WCHAR* base_path, const WCHAR* path, UINT32 Pat
file->CreateDisposition = CreateDisposition;
file->CreateOptions = CreateOptions;
file->SharedAccess = SharedAccess;
- drive_file_set_fullpath(file, drive_file_combine_fullpath(base_path, path, PathLength));
+ drive_file_set_fullpath(file, drive_file_combine_fullpath(base_path, path, PathWCharLength));
if (!drive_file_init(file))
{
@@ -714,13 +741,10 @@ BOOL drive_file_set_information(DRIVE_FILE* file, UINT32 FsInformationClass, UIN
return FALSE;
fullpath = drive_file_combine_fullpath(file->basepath, (WCHAR*)Stream_Pointer(input),
- FileNameLength);
+ FileNameLength / sizeof(WCHAR));
if (!fullpath)
- {
- WLog_ERR(TAG, "drive_file_combine_fullpath failed!");
return FALSE;
- }
#ifdef _WIN32
@@ -759,7 +783,7 @@ BOOL drive_file_set_information(DRIVE_FILE* file, UINT32 FsInformationClass, UIN
}
BOOL drive_file_query_directory(DRIVE_FILE* file, UINT32 FsInformationClass, BYTE InitialQuery,
- const WCHAR* path, UINT32 PathLength, wStream* output)
+ const WCHAR* path, UINT32 PathWCharLength, wStream* output)
{
size_t length;
WCHAR* ent_path;
@@ -773,7 +797,7 @@ BOOL drive_file_query_directory(DRIVE_FILE* file, UINT32 FsInformationClass, BYT
if (file->find_handle != INVALID_HANDLE_VALUE)
FindClose(file->find_handle);
- ent_path = drive_file_combine_fullpath(file->basepath, path, PathLength);
+ ent_path = drive_file_combine_fullpath(file->basepath, path, PathWCharLength);
/* open new search handle and retrieve the first entry */
file->find_handle = FindFirstFileW(ent_path, &file->find_data);
free(ent_path);
diff --git a/channels/drive/client/drive_file.h b/channels/drive/client/drive_file.h
index ed789d6f0..6d3bd7045 100644
--- a/channels/drive/client/drive_file.h
+++ b/channels/drive/client/drive_file.h
@@ -51,9 +51,9 @@ struct _DRIVE_FILE
UINT32 CreateOptions;
};
-DRIVE_FILE* drive_file_new(const WCHAR* base_path, const WCHAR* path, UINT32 PathLength, UINT32 id,
- UINT32 DesiredAccess, UINT32 CreateDisposition, UINT32 CreateOptions,
- UINT32 FileAttributes, UINT32 SharedAccess);
+DRIVE_FILE* drive_file_new(const WCHAR* base_path, const WCHAR* path, UINT32 PathWCharLength,
+ UINT32 id, UINT32 DesiredAccess, UINT32 CreateDisposition,
+ UINT32 CreateOptions, UINT32 FileAttributes, UINT32 SharedAccess);
BOOL drive_file_free(DRIVE_FILE* file);
BOOL drive_file_open(DRIVE_FILE* file);
@@ -64,6 +64,6 @@ BOOL drive_file_query_information(DRIVE_FILE* file, UINT32 FsInformationClass, w
BOOL drive_file_set_information(DRIVE_FILE* file, UINT32 FsInformationClass, UINT32 Length,
wStream* input);
BOOL drive_file_query_directory(DRIVE_FILE* file, UINT32 FsInformationClass, BYTE InitialQuery,
- const WCHAR* path, UINT32 PathLength, wStream* output);
+ const WCHAR* path, UINT32 PathWCharLength, wStream* output);
#endif /* FREERDP_CHANNEL_DRIVE_FILE_H */
diff --git a/channels/drive/client/drive_main.c b/channels/drive/client/drive_main.c
index 1b5422522..d3776381c 100644
--- a/channels/drive/client/drive_main.c
+++ b/channels/drive/client/drive_main.c
@@ -184,8 +184,8 @@ static UINT drive_process_irp_create(DRIVE_DEVICE* drive, IRP* irp)
path = (const WCHAR*)Stream_Pointer(irp->input);
FileId = irp->devman->id_sequence++;
- file = drive_file_new(drive->path, path, PathLength, FileId, DesiredAccess, CreateDisposition,
- CreateOptions, FileAttributes, SharedAccess);
+ file = drive_file_new(drive->path, path, PathLength / sizeof(WCHAR), FileId, DesiredAccess,
+ CreateDisposition, CreateOptions, FileAttributes, SharedAccess);
if (!file)
{
@@ -636,8 +636,8 @@ static UINT drive_process_irp_query_directory(DRIVE_DEVICE* drive, IRP* irp)
irp->IoStatus = STATUS_UNSUCCESSFUL;
Stream_Write_UINT32(irp->output, 0); /* Length */
}
- else if (!drive_file_query_directory(file, FsInformationClass, InitialQuery, path, PathLength,
- irp->output))
+ else if (!drive_file_query_directory(file, FsInformationClass, InitialQuery, path,
+ PathLength / sizeof(WCHAR), irp->output))
{
irp->IoStatus = drive_map_windows_err(GetLastError());
}
--
2.37.1
|
