712fc9803a
Summary: This is an initial implementation of a Hardened Allocator based on Sanitizer Common's CombinedAllocator. It aims at mitigating heap based vulnerabilities by adding several features to the base allocator, while staying relatively fast. The following were implemented: - additional consistency checks on the allocation function parameters and on the heap chunks; - use of checksum protected chunk header, to detect corruption; - randomness to the allocator base; - delayed freelist (quarantine), to mitigate use after free and overall determinism. Additional mitigations are in the works. Reviewers: eugenis, aizatsky, pcc, krasin, vitalybuka, glider, dvyukov, kcc Subscribers: kubabrecka, filcab, llvm-commits Differential Revision: http://reviews.llvm.org/D20084 llvm-svn: 271968
82 lines
2.3 KiB
C++
82 lines
2.3 KiB
C++
//===-- scudo_flags.cpp -----------------------------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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///
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/// Hardened Allocator flag parsing logic.
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///
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//===----------------------------------------------------------------------===//
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#include "scudo_flags.h"
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#include "scudo_utils.h"
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#include "sanitizer_common/sanitizer_flags.h"
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#include "sanitizer_common/sanitizer_flag_parser.h"
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namespace __scudo {
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Flags scudo_flags_dont_use_directly; // use via flags().
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void Flags::setDefaults() {
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#define SCUDO_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
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#include "scudo_flags.inc"
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#undef SCUDO_FLAG
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}
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static void RegisterScudoFlags(FlagParser *parser, Flags *f) {
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#define SCUDO_FLAG(Type, Name, DefaultValue, Description) \
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RegisterFlag(parser, #Name, Description, &f->Name);
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#include "scudo_flags.inc"
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#undef SCUDO_FLAG
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}
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void initFlags() {
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SetCommonFlagsDefaults();
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{
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CommonFlags cf;
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cf.CopyFrom(*common_flags());
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cf.exitcode = 1;
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OverrideCommonFlags(cf);
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}
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Flags *f = getFlags();
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f->setDefaults();
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FlagParser scudo_parser;
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RegisterScudoFlags(&scudo_parser, f);
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RegisterCommonFlags(&scudo_parser);
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scudo_parser.ParseString(GetEnv("SCUDO_OPTIONS"));
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InitializeCommonFlags();
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// Sanity checks and default settings for the Quarantine parameters.
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if (f->QuarantineSizeMb < 0) {
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const int DefaultQuarantineSizeMb = 64;
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f->QuarantineSizeMb = DefaultQuarantineSizeMb;
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}
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// We enforce an upper limit for the quarantine size of 4Gb.
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if (f->QuarantineSizeMb > (4 * 1024)) {
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dieWithMessage("ERROR: the quarantine size is too large\n");
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}
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if (f->ThreadLocalQuarantineSizeKb < 0) {
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const int DefaultThreadLocalQuarantineSizeKb = 1024;
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f->ThreadLocalQuarantineSizeKb = DefaultThreadLocalQuarantineSizeKb;
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}
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// And an upper limit of 128Mb for the thread quarantine cache.
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if (f->ThreadLocalQuarantineSizeKb > (128 * 1024)) {
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dieWithMessage("ERROR: the per thread quarantine cache size is too "
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"large\n");
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}
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}
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Flags *getFlags() {
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return &scudo_flags_dont_use_directly;
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}
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}
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