Answer in brief
CVE-2026-80633 records a High severity (CVSS 8.8) vulnerability in iommufd: Take dma_resv lock before dma_buf_unpin() in release path. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8c5f9645c3893f0db679d9affe4fe4e665b990dd <cc69d0332421fd2943b66dbe5e597bf4fd5af126 || >=8c5f9645c3893f0db679d9affe4fe4e665b990dd <e745cd2c749e557c14a15ac931761c3f58c24489 | cc69d0332421fd2943b66dbe5e597bf4fd5af126, e745cd2c749e557c14a15ac931761c3f58c24489 |
| Linux/Linuxgeneric | 7.1 | Not reported |
Published upstream
Aug 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 28, 2026
In the Linux kernel, the following vulnerability has been resolved: iommufd: Take dma_resv lock before dma_buf_unpin() in release path dma_buf_unpin() requires the caller to hold the exporter's dma_resv lock: void dma_buf_unpin(struct dma_buf_attachment *attach) { ... dma_resv_assert_held(dmabuf->resv); ... } iopt_release_pages() calls dma_buf_unpin() without taking that lock, so every iommufd_ioas_destroy()/iommufd_ioas_unmap() that releases the last reference on a DMABUF-backed iopt_pages triggers a WARN. This was hit while running tools/testing/selftests/iommu/iommufd: WARNING: drivers/dma-buf/dma-buf.c:1137 at dma_buf_unpin+0x62/0x70 RIP: 0010:dma_buf_unpin+0x62/0x70 Call Trace: <TASK> dma_buf_unpin+0x62/0x70 iopt_release_pages+0xe4/0x190 iopt_unmap_iova_range+0x1c7/0x290 iopt_unmap_all+0x1a/0x30 iommufd_ioas_destroy+0x1d/0x50 iommufd_fops_release+0x93/0x150 __fput+0xfc/0x2c0 __x64_sys_close+0x3d/0x80 do_syscall_64+0x65/0x180 </TASK> Take the dma_resv lock around dma_buf_unpin() in iopt_release_pages(), matching the iopt_map_dmabuf() convention. dma_buf_detach() acquires the reservation lock internally, so it must remain outside the locked region.
Quoted source text, attributed separately from HOL analysis.