CVE-2026-68413: Linux Kernel Memory Leak Vulnerability

CVE-2026-68413 Overview

CVE-2026-68413 is a memory leak vulnerability in the Linux kernel's ipw2100 Wi-Fi driver. The flaw exists in the ipw2100_pci_init_one() PCI probe function. Memory allocated by ipw2100_alloc_device() is not released along several error paths, leaking kernel memory when device initialization fails.

The upstream fix converts the direct return statements in those error paths into goto jumps that reach the proper cleanup label. The error path for pci_enable_device() failure is handled inline because priv is not yet set at that point.

Critical Impact
Repeated probe failures on affected ipw2100 hardware can exhaust kernel memory over time, resulting in resource exhaustion on long-running Linux systems.

Affected Products

Linux kernel builds that include the ipw2100 wireless driver (drivers/net/wireless/intel/ipw2x00/ipw2100.c)
Systems using Intel PRO/Wireless 2100 network adapters
Distributions shipping vulnerable stable kernel branches prior to the referenced patches

Discovery Timeline

2026-08-10 - CVE-2026-68413 published to NVD
2026-08-10 - Last updated in NVD database

Technical Details for CVE-2026-68413

Vulnerability Analysis

The defect resides in the PCI probe routine ipw2100_pci_init_one() in the ipw2100 wireless driver. The function calls ipw2100_alloc_device() early in initialization to allocate the private device structure. Subsequent initialization steps can fail, and several of those failure branches use a bare return statement rather than jumping to the shared cleanup path. As a result, the allocation from ipw2100_alloc_device() is never freed on those error legs.

The consequence is a kernel-space memory leak on each failed probe. Because the leak is triggered by driver-initialization error paths, it is most observable during repeated hotplug events, driver reload cycles, or hardware-fault conditions on systems fitted with Intel PRO/Wireless 2100 adapters.

Root Cause

The root cause is inconsistent error handling in ipw2100_pci_init_one(). Some failure paths correctly release resources through a common label, while others return directly and skip cleanup. This asymmetry violates the standard Linux kernel pattern of centralizing error unwinding via goto labels [CWE-401: Missing Release of Memory after Effective Lifetime].

Attack Vector

This is a local, low-privilege reliability issue rather than a remote exploitation primitive. Triggering the leak requires reaching the failing error paths in the driver's PCI probe routine, typically through repeated driver load/unload, PCI hotplug events, or induced initialization failures on hosts that expose ipw2100 hardware. Sustained triggering can degrade kernel memory availability and destabilize long-lived systems.

No verified exploit or public proof-of-concept is available for this issue. The vulnerability was resolved through the following stable-tree commits: 0d388f62031d, 7cbda50eebcd, 836a19c654dc, f442e581a889, and f75b9a2a9d83. See the Linux Kernel Patch Note for the reference implementation.

Detection Methods for CVE-2026-68413

Indicators of Compromise

Growth of unaccounted kernel slab allocations correlated with ipw2100 driver load or PCI probe failures.
Repeated ipw2100 probe error messages in dmesg or journalctl -k output without corresponding successful device registration.
Gradual reduction in MemAvailable reported by /proc/meminfo on systems that repeatedly retry ipw2100 initialization.

Detection Strategies

Audit installed kernel versions with uname -r and compare against distribution advisories referencing the listed stable commits.
Monitor dmesg for ipw2100 probe failures, particularly around pci_enable_device() and post-ipw2100_alloc_device() initialization stages.
Use slabtop or /proc/slabinfo to observe abnormal growth of allocations attributable to the driver's private device structure.

Monitoring Recommendations

Track kernel memory metrics (MemAvailable, Slab, SReclaimable) with long-term telemetry to detect slow leaks.
Alert on repeated PCI probe failure log entries for ipw2100 devices on the same host.
Include kernel version and patch level in configuration-management inventories to identify unpatched hosts.

How to Mitigate CVE-2026-68413

Immediate Actions Required

Update to a Linux kernel that includes one of the fix commits: 0d388f62031d, 7cbda50eebcd, 836a19c654dc, f442e581a889, or f75b9a2a9d83.
Apply vendor kernel updates from your Linux distribution as soon as they become available.
On systems that do not require Intel PRO/Wireless 2100 hardware, blacklist the ipw2100 module to eliminate the code path entirely.

Patch Information

The fix converts unsafe return statements in ipw2100_pci_init_one() into goto jumps toward the shared cleanup label, and handles the pci_enable_device() failure branch inline because priv has not yet been allocated. Refer to the upstream commits: 0d388f62031d, 7cbda50eebcd, 836a19c654dc, f442e581a889, and f75b9a2a9d83.

Workarounds

Prevent driver load on systems that do not use the hardware by adding blacklist ipw2100 to a file under /etc/modprobe.d/.
Avoid automation that repeatedly reloads the ipw2100 module on hosts where probe failures are known to occur.
Physically remove or disable unused Intel PRO/Wireless 2100 adapters where feasible.

bash

# Blacklist the ipw2100 driver on hosts that do not require it
echo "blacklist ipw2100" | sudo tee /etc/modprobe.d/blacklist-ipw2100.conf
sudo update-initramfs -u
# Verify the module is not loaded after reboot
lsmod | grep ipw2100