Linux Segmentation Fault (Segfault) Error Fix

What Does This Error Mean?

A segmentation fault (segfault) means a program tried to access a part of memory it was not allowed to use, and Linux stopped it. You see 'Segmentation fault (core dumped)' in the terminal. This usually means the program has a bug, a library it depends on is corrupted, or your hardware (RAM) is faulty.

Affected Models

Ubuntu
Debian
Fedora
CentOS
Arch Linux
Linux Mint
openSUSE

Common Causes

The program itself has a software bug causing it to access memory incorrectly
A shared library the program depends on is corrupted or the wrong version
Faulty RAM is causing random memory corruption that triggers the segfault
The program is incompatible with the current version of the kernel or a library
File system corruption has caused a program binary to be partially damaged

How to Fix It

Reinstall the crashing program. Run: sudo apt reinstall [program-name] (Debian/Ubuntu) or sudo dnf reinstall [program-name] (Fedora). This replaces any corrupted binary or library files.

Corrupted program files are a common and easy-to-fix cause of segfaults.
Update all packages. Run: sudo apt update && sudo apt upgrade (Debian/Ubuntu) or sudo dnf upgrade (Fedora). An outdated library that the program depends on can cause segfaults.

Library version mismatches are a very common cause of segfaults on Linux, especially after a partial update.
Check for missing libraries. Run the program from the terminal. If you see 'error while loading shared libraries,' install the missing package: sudo apt install [library-name]

The error message usually names the missing library file. Search for the package that provides it using: apt-file search [library-name]
Test your RAM. Boot from a USB drive with Memtest86+ and run a full memory test. Faulty RAM can cause random segfaults in any program.

If Memtest86+ finds any errors, even a single one, your RAM needs to be replaced. There is no software fix for bad RAM.
Check system file integrity. Run: sudo apt install --reinstall coreutils (Debian/Ubuntu) to reinstall core system tools. If many programs segfault, the base system files may be corrupted.

On Fedora/Red Hat systems, use: sudo rpm -Va to verify all installed packages and find corrupted files.

When to Call a Professional

If segfaults happen in many different programs, the likely cause is faulty RAM or kernel-level issues. Test your RAM with Memtest86+ and consider replacing it if errors are found. For segfaults in a specific application, report the bug to the application's developer.

Frequently Asked Questions

Does 'core dumped' mean I lost data?

No — 'core dumped' means Linux saved a file called 'core' containing the program's memory at the time of the crash. This file is used by developers to debug what went wrong. Your personal files are not affected. You can delete the core dump file if you do not plan to use it for debugging.

A program I wrote keeps segfaulting. How do I find the bug?

Use a debugger like GDB: run gdb ./your-program then type run. When the segfault occurs, type bt to see the backtrace — a list of function calls that led to the crash. The line at the top of the backtrace is where the crash happened.

Is a segfault dangerous to my system?

No — a segfault only crashes the one program that triggered it. Linux prevents the crashed program from affecting other programs or the kernel. Your system, other apps, and your files are completely unaffected.