Inspektor Gadget is a set of tools and framework for data collection and system inspection on Kubernetes clusters and Linux hosts using eBPF. From 0.27.0 until 0.53.1, the uprobe library resolver can allow an unprivileged container to consume excessive CPU and block other containers from starting by supplying a crafted /etc/ld.so.cache file while an uprobe-based gadget is active. The parser in pkg/uprobetracer/ldcache_parser.go trusts EntryCount enough to perform excessive iteration, computes cache1Len with overflowing uint32 arithmetic, and repeatedly calls readStringFromBytes in pkg/uprobetracer/bytes.go, where byte-by-byte immutable string concatenation produces quadratic work. While this processing occurs, pkg/container-hook holds the fanotify container-start pause, allowing a crafted cache to delay startup for roughly a minute, prevent Docker from starting other containers, and degrade monitoring. Processing caches from already-running containers can still consume CPU but does not hold the new-container startup pause, and the advisory establishes no confidentiality or integrity impact. This issue is fixed in version 0.53.1.

Affected: Go: github.com/inspektor-gadget/inspektor-gadget

## Summary

An unprivileged container can block all other containers from starting on the same host by placing a crafted `/etc/ld.so.cache` file in its filesystem. When Inspektor Gadget attaches any uprobe-based gadget, it parses this file in the container startup path. A malicious cache causes ~53 seconds of CPU burn, during which Docker cannot start any other container. No special capabilities are required.

## Severity

To be assessed — Availability impact, no confidentiality or integrity impact.

## Affected Versions

All versions of Inspektor Gadget that support uprobe-based gadgets (trace_malloc, trace_open, trace_ssl, trace_grpc, etc.).

## Description

When Inspektor Gadget attaches uprobe-based gadgets to containers, it resolves library paths by parsing the container's `/etc/ld.so.cache` file (`pkg/uprobetracer/ldcache_parser.go`). This file is fully controlled by the container.

The parser has three vulnerabilities:

1. **Quadratic string building** (`pkg/uprobetracer/bytes.go:36-44`): The `readStringFromBytes` function concatenates one byte at a time (`res += string(data[i])`), which is O(n²) in Go due to string immutability. With a 16MB cache file containing large regions without null terminators, this causes massive CPU and memory churn.

2. **Insufficient entry count validation** (`pkg/uprobetracer/ldcache_parser.go:120`): The `EntryCount` field is read directly from the untrusted file. While a per-entry bounds check prevents out-of-bounds access, the loop stil…