protonscr

Steam spawns thousands of `conhost.exe` processes on startup

steamclosed Distro Family: Arch
ValveSoftware/steam-for-linux#12341 · opened 2025-09-22 by HazmatPants · updated 2025-11-01 · 3 comments · github
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HHazmatPants 2025-09-22 github

System Information

Distro: Arch Linux

Kernel: 6.16.8-arch2-1 (64-bit)

CPU: quad core Intel Core i5-7400

GPU: NVIDIA GTX 960, Driver version 580.82.09

Steam package: steam (runtime)

Working workaround: steam-native package works fine

inxi -Fazy output: system-info.txt

Issue Description

When launching Steam from the standard runtime package (steam), the client immediately spawns thousands of conhost.exe (Wine) processes, quickly exhausting all memory until the kernel OOM killer terminates Steam. This occurs before launching any game.

Running Steam with the native package (steam-native) works normally, which suggests the issue lies in the Steam Runtime environment and not the client itself or Proton prefixes.

Steps for Reproduction

  1. Install Steam from Arch’s official repos (steam).

  2. Launch steam from terminal.

  3. Observe runaway conhost.exe / Wine processes until OOM kill.

Observed Behavior

Terminal log is flooded with Wine crash errors:

wine: Unhandled page fault on read access to 000000000000036E at address 00006FFFFE5D6FC0 (thread xxxx), starting debugger...

Thousands of Wine processes are spawned, system memory is consumed and Steam is killed by the kernel.

Expected Behavior

Steam should launch normally, without invoking Proton/Wine at startup.

Additional Notes

  • Removing Proton prefixes did not resolve the issue.

  • Happens consistently on every launch of steam (runtime).

  • steam-native package runs fine.

  • Flatpak Steam not tested.

Logs: steam-logs.tar.gz

Kkisak-valve maintainer 2025-09-22 github

Hello @HazmatPants, using a tool like htop in tree view mode, can you tell which compatibility tool is active when these processes are spawned?

HHazmatPants 2025-09-22 github

Hi @kisak-valve, I can't seem to reproduce the issue again, I tried launching the normal non-native client (steam) multiple times, but it no longer spawns the Wine processes. I'm unsure what changed, so it may have been fixed by a Steam client or Arch package update. I'll keep testing a bit and report back if it happens again.

Kkisak-valve maintainer 2025-11-01 github

Closing per the last comment.

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