1 // Copyright (c) 2013 Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 // * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30 // exploitability_linux.cc: Linux specific exploitability engine.
31 //
32 // Provides a guess at the exploitability of the crash for the Linux
33 // platform given a minidump and process_state.
34 //
35 // Author: Matthew Riley
36
37 #include "processor/exploitability_linux.h"
38
39 #include "google_breakpad/processor/process_state.h"
40 #include "google_breakpad/processor/call_stack.h"
41 #include "google_breakpad/processor/stack_frame.h"
42
43 namespace {
44
45 // This function in libc is called if the program was compiled with
46 // -fstack-protector and a function's stack canary changes.
47 const char kStackCheckFailureFunction[] = "__stack_chk_fail";
48
49 // This function in libc is called if the program was compiled with
50 // -D_FORTIFY_SOURCE=2, a function like strcpy() is called, and the runtime
51 // can determine that the call would overflow the target buffer.
52 const char kBoundsCheckFailureFunction[] = "__chk_fail";
53
54 } // namespace
55
56 namespace google_breakpad {
57
ExploitabilityLinux(Minidump * dump,ProcessState * process_state)58 ExploitabilityLinux::ExploitabilityLinux(Minidump *dump,
59 ProcessState *process_state)
60 : Exploitability(dump, process_state) { }
61
CheckPlatformExploitability()62 ExploitabilityRating ExploitabilityLinux::CheckPlatformExploitability() {
63 // Check the crashing thread for functions suggesting a buffer overflow or
64 // stack smash.
65 if (process_state_->requesting_thread() != -1) {
66 CallStack* crashing_thread =
67 process_state_->threads()->at(process_state_->requesting_thread());
68 const vector<StackFrame*>& crashing_thread_frames =
69 *crashing_thread->frames();
70 for (size_t i = 0; i < crashing_thread_frames.size(); ++i) {
71 if (crashing_thread_frames[i]->function_name ==
72 kStackCheckFailureFunction) {
73 return EXPLOITABILITY_HIGH;
74 }
75
76 if (crashing_thread_frames[i]->function_name ==
77 kBoundsCheckFailureFunction) {
78 return EXPLOITABILITY_HIGH;
79 }
80 }
81 }
82
83 return EXPLOITABILITY_NONE;
84 }
85
86 } // namespace google_breakpad
87