# CVE-2026-98024: Linux kernel s390/ism memory corruption in error handling

Source: https://junglewise.ai/threats/cve-2026-98024-in-the-linux-kernel-the-following-vulnerability-has-been-resolved  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-25. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-98024 · Severity: info · Published 2026-09-25

The Linux kernel's s390 ISM (Isolated Shared Memory) driver had a bug in its error handling path where memory allocated as a folio was incorrectly freed using kfree(), potentially corrupting the slab allocator. This could cause kernel instability or crashes when the ISM driver fails to allocate receive message buffers. The fix corrects the deallocation to use folio_put() and prevents use-after-free errors.

Technologies: [Unknown Linux kernel](https://junglewise.ai/threats/technologies/unknown-linux-kernel). Vendors: [Unknown](https://junglewise.ai/threats/vendors/unknown).

## Quick answers

**Is CVE-2026-98024 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-98024 being exploited in the wild.

**How severe is CVE-2026-98024?** Informational severity, published 25 September 2026.

**Which products and versions are affected?** Unknown Linux kernel Multiple stable versions (fix applied across linux-5.x through linux-7.x).

**Is there a fix for CVE-2026-98024?** A patch was published on 2026-09-21. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-98024 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-98024?** Check whether you run Unknown Linux kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in the ism_alloc_dmb() function in drivers/s390/net/ism_drv.c, where folio_alloc() allocates memory but the error path incorrectly calls kfree() instead of folio_put(). This mismatch between allocation and deallocation methods causes slab allocator corruption. Additionally, the pointer is not reset after freeing, leading to potential use-after-free. The fix applies folio_put() on the error path and nullifies the pointer to prevent UAF by callers.

## Affected products

- <UNKNOWN> Linux kernel Multiple stable versions (fix applied across linux-5.x through linux-7.x)

## Timeline

- 2026-09-25: disclosed
- 2026-09-21: patched

## References

- [https://git.kernel.org/stable/c/60983356fab0c1171c5cb1b56a36349ebadc608e](https://git.kernel.org/stable/c/60983356fab0c1171c5cb1b56a36349ebadc608e)
- [https://git.kernel.org/stable/c/890e2ef726904d1d8328e4b9f5090eeb8761b9d1](https://git.kernel.org/stable/c/890e2ef726904d1d8328e4b9f5090eeb8761b9d1)

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