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AddressSanitizer
A code sanitizer is a programming tool that detects bugs in the form of undefined or suspicious behavior by a compiler inserting instrumentation code at runtime. The class of tools was first introduced by Google's AddressSanitizer (or ASan) of 2012, which uses directly mapped shadow memory to detect memory corruption such as buffer overflows or accesses to a dangling pointer (use-after-free). AddressSanitizer Google's ASan, introduced in 2012, uses a shadow memory scheme to detect memory bugs. It is available in: * Clang (starting from version 3.1) * GCC (starting from version 4.8) * Xcode (starting from version 7.0) * MSVC (widely available starting from version 16.9). On average, the instrumentation increases processing time by about 73% and memory usage by 240%. There is a hardware-accelerated ASan called HWAsan available for AArch64 and (in a limited fashion) x86_64. AddressSanitizer does not detect any uninitialized memory reads (but this is detected by MemorySanitizer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel MPX
Intel MPX (Memory Protection Extensions) are a discontinued set of extensions to the x86 instruction set architecture. With compiler, runtime library and operating system support, Intel MPX claimed to enhance security to software by checking pointer references whose normal compile-time intentions are maliciously exploited at runtime due to buffer overflows. In practice, there have been too many flaws discovered in the design for it to be useful, and support has been deprecated or removed from most compilers and operating systems. Intel has listed MPX as removed in 2019 and onward hardware in section 2.5 of its Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 1. Extensions Intel MPX introduces new bounds registers, and new instruction set extensions that operate on these registers. Additionally, there is a new set of "bound tables" that store bounds beyond what can fit in the bounds registers. MPX uses four new 128-bit bounds registers, BND0 to BND3, each st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shadow Memory
In computing, shadow memory is a technique used to track and store information on computer memory used by a computer program, program during its execution. Shadow memory consists of shadow bytes that map to individual bits or one or more bytes in main memory. These shadow bytes are typically invisible to the original program and are used to record information about the original piece of data. Technique The technique is utilized by memory-error checkers that can store information on which parts of memory have been allocated to the program being checked. This shadow memory is then used for detecting and reporting incorrect accesses of memory, even though the program may not be crashing due to a segmentation fault or similar. An error checker may also store additional information on memory such as which bits have been defined and which ones do not. Memcheck, part of the Valgrind suite, uses this to detect undefined behavior resulting from acting on or printing undefined memory values. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valgrind
Valgrind () is a programming tool for memory debugging, memory leak detection, and profiling. Valgrind was originally designed to be a freely licensed memory debugging tool for Linux on x86, but has since evolved to become a generic framework for creating dynamic analysis tools such as checkers and profilers. Overview Valgrind is in essence a virtual machine using just-in-time compilation techniques, including dynamic recompilation. Nothing from the original program ever gets run directly on the host processor. Instead, Valgrind first translates the program into a temporary, simpler form called intermediate representation (IR), which is a processor-neutral, static single assignment form-based form. After the conversion, a tool (see below) is free to do whatever transformations it would like on the IR, before Valgrind translates the IR back into machine code and lets the host processor run it. Valgrind recompiles binary code to run on host and target (or simulated) CPUs of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Corruption
Memory corruption occurs in a computer program when the contents of a memory location are modified due to programmatic behavior that exceeds the intention of the original programmer or program/language constructs; this is termed as violation of memory safety. The most likely causes of memory corruption are programming errors (software bugs). When the corrupted memory contents are used later in that program, it leads either to program crash or to strange and bizarre program behavior. Nearly 10% of application crashes on Windows systems are due to heap corruption.{{Cite web, last=Radich, first=Q., last2=Sherer, first2=T., last3=Sharkey, first3=K., last4=Batchelor, first4=D., last5=Kennedy, first5=J. T., last6=Mabee, first6=D., last7=Coulter, first7=D., last8=Michael, first8=S., date=28 April 2021, title=Application Verifier (Windows 7 and Windows Server 2008 R2 Application Quality Cookbook) - Win32 apps, publisher=Microsoft Developer Network, url=https://docs.microsoft.com/en-us/wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dangling Pointer
Dangling pointers and wild pointers in computer programming are pointers that do not point to a valid object of the appropriate type. These are special cases of memory safety violations. More generally, dangling references and wild references are references that do not resolve to a valid destination. Dangling pointers arise during object destruction, when an object that is pointed to by a given pointer is deleted or deallocated, without modifying the value of that said pointer, so that the pointer still points to the memory location of the deallocated memory. The system may reallocate the previously freed memory, and if the program then dereferences the (now) dangling pointer, '' unpredictable behavior may result'', as the memory may now contain completely different data. If the program writes to memory referenced by a dangling pointer, a silent corruption of unrelated data may result, leading to subtle bugs that can be extremely difficult to find. If the memory has been real ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fuzzing
In programming and software development, fuzzing or fuzz testing is an automated software testing technique that involves providing invalid, unexpected, or random data as inputs to a computer program. The program is then monitored for exceptions such as crashes, failing built-in code assertions, or potential memory leaks. Typically, fuzzers are used to test programs that take structured inputs. This structure is specified, such as in a file format or protocol and distinguishes valid from invalid input. An effective fuzzer generates semi-valid inputs that are "valid enough" in that they are not directly rejected by the parser, but do create unexpected behaviors deeper in the program and are "invalid enough" to expose corner cases that have not been properly dealt with. For the purpose of security, input that crosses a trust boundary is often the most useful. For example, it is more important to fuzz code that handles a file uploaded by any user than it is to fuzz the code ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Bug
A software bug is a design defect ( bug) in computer software. A computer program with many or serious bugs may be described as ''buggy''. The effects of a software bug range from minor (such as a misspelled word in the user interface) to severe (such as frequent crashing). In 2002, a study commissioned by the US Department of Commerce's National Institute of Standards and Technology concluded that "software bugs, or errors, are so prevalent and so detrimental that they cost the US economy an estimated $59 billion annually, or about 0.6 percent of the gross domestic product". Since the 1950s, some computer systems have been designed to detect or auto-correct various software errors during operations. History Terminology ''Mistake metamorphism'' (from Greek ''meta'' = "change", ''morph'' = "form") refers to the evolution of a defect in the final stage of software deployment. Transformation of a ''mistake'' committed by an analyst in the early stages of the softw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firefox
Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current and anticipated web standards. Firefox is available for Windows 10 or later versions of Windows, macOS, and Linux. Its unofficial ports are available for various Unix and Unix-like operating systems, including FreeBSD, OpenBSD, NetBSD, and other operating systems, such as ReactOS. Firefox is also available for Android and iOS. However, as with all other iOS web browsers, the iOS version uses the WebKit layout engine instead of Gecko due to platform requirements. An optimized version is also available on the Amazon Fire TV as one of the two main browsers available with Amazon's Silk Browser. Firefox is the spiritual successor of Netscape Navigator, as the Mozilla community was created by Netscape in 1998, before its acqui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shadow Stack
In computer security, a shadow stack is a mechanism for protecting a procedure's stored return address, such as from a stack buffer overflow. The shadow stack itself is a second, separate stack that "shadows" the program call stack. In the function prologue, a function stores its return address to both the call stack and the shadow stack. In the function epilogue, a function loads the return address from both the call stack and the shadow stack, and then compares them. If the two records of the return address differ, then an attack is detected; the typical course of action is simply to terminate the program or alert system administrators about a possible intrusion attempt. A shadow stack is similar to stack canaries in that both mechanisms aim to maintain the control-flow integrity of the protected program by detecting attacks that tamper the stored return address by an attacker during an exploitation attempt. Shadow stacks can be implemented by recompiling programs with modif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium (web Browser)
Chromium is a free and open-source web browser project, primarily developed and maintained by Google. It is a widely-used codebase, providing the vast majority of source code, code for Google Chrome and many other browsers, including Microsoft Edge, Samsung Internet, and Opera (web browser), Opera. The code is also used by several application framework, app frameworks. Licensing Chromium is a free and open-source software project. The Google-authored portion is shared under the BSD licenses#3-clause license ("BSD License 2.0", "Revised BSD License", "New BSD License", or "Modified BSD License"), 3-clause BSD license. Third party dependencies are subject to a variety of licenses, including MIT License, MIT, GNU Lesser General Public License, LGPL, Ms-PL, and an Mozilla Public License, MPL/GNU General Public License, GPL/GNU Lesser General Public License, LGPL multi-licensing, tri-license. This licensing permits any party to compiler, build the codebase and share the resulting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X86-64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit extension of the x86 instruction set architecture, instruction set. It was announced in 1999 and first available in the AMD Opteron family in 2003. It introduces two new operating modes: 64-bit mode and compatibility mode, along with a new four-level paging mechanism. In 64-bit mode, x86-64 supports significantly larger amounts of virtual memory and physical memory compared to its 32-bit computing, 32-bit predecessors, allowing programs to utilize more memory for data storage. The architecture expands the number of general-purpose registers from 8 to 16, all fully general-purpose, and extends their width to 64 bits. Floating-point arithmetic is supported through mandatory SSE2 instructions in 64-bit mode. While the older x87 FPU and MMX registers are still available, they are generally superseded by a set of sixteen 128-bit Processor register, vector registers (XMM registers). Each of these vector registers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FFmpeg
FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing video and audio files. It is widely used for format transcoding, basic editing (trimming and concatenation), video scaling, video post-production effects, and standards compliance ( SMPTE, ITU). FFmpeg also includes other tools: ffplay, a simple media player, and ffprobe, a command-line tool to display media information. Among included libraries are libavcodec, an audio/video codec library used by many commercial and free software products, libavformat (Lavf), an audio/video container mux and demux library, and libavfilter, a library for enhancing and editing filters through a GStreamer-like filtergraph. FFmpeg is part of the workflow of many other software projects, and its libraries are a core part of software media players such as V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
