CVE-2026-43128: linux kernel Double Free — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/umem: Fix double dma_buf_unpin in failure path In ib_umem_dmabuf_get_pinned_with_dma_device(), the call to ib_umem_dmabuf_map_pages() can fail. If this occurs, the dmabuf is immediately unpinned but the umem_dmabuf->pinned flag is still set. Then, when ib_umem_release() is called, it calls ib_umem_dmabuf_revoke() which will call dma_buf_unpin() again. Fix this by removing the immediate unpin upon failure and just let the ib_umem_release/revoke path handle it. This also ensures the proper unmap-unpin unwind ordering if the dmabuf_map_pages call happened to fail due to dma_resv_wait_timeout (and therefore has a non-NULL umem_dmabuf->sgt).

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-415 CWE-415

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.16 — 6.1.165
linux	linux_kernel	6.2 — 6.6.128
linux	linux_kernel	6.7 — 6.12.75
linux	linux_kernel	6.13 — 6.18.16
linux	linux_kernel	6.19 — 6.19.6
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/104016eb671e19709721c1b0048dd912dc2e96be https://git.kernel.org/stable/c/40126bcbefa79ea86672e05dae608596bab38319 https://git.kernel.org/stable/c/70542b69abff34d24b11ae0bb200cc7a766d18df https://git.kernel.org/stable/c/b324327ff6f48d8065dca67eb3b91357e72726bd https://git.kernel.org/stable/c/ba3bf0f1bf1d5d0404678485e872980532fcc2c4 https://git.kernel.org/stable/c/d3e32e2f3262f1b25d77c085ace38e2cc4ad75cf

Frequently Asked Questions

What is CVE-2026-43128? +

In the Linux kernel, the following vulnerability has been resolved: RDMA/umem: Fix double dma_buf_unpin in failure path In ib_umem_dmabuf_get_pinned_with_dma_device(), the call to ib_umem_dmabuf_map_pages() can fail. If this occurs, the dmabuf is immediately unpinned but the umem_dmabuf->pinned flag is still set. Then, when ib_umem_release() is called, it calls ib_umem_dmabuf_revoke() which will call dma_buf_unpin() again. Fix this by removing the immediate unpin upon failure and just let the ib_umem_release/revoke path handle it. This also ensures the proper unmap-unpin unwind ordering if the dmabuf_map_pages call happened to fail due to dma_resv_wait_timeout (and therefore has a non-NULL umem_dmabuf->sgt). It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-43128? +

CVE-2026-43128 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-43128? +

CVE-2026-43128 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-43128? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-43128