Bug 2536339 (CVE-2026-90387) - CVE-2026-90387 kernel: swiotlb: Preserve allocation virtual address for dynamic pools
Summary: CVE-2026-90387 kernel: swiotlb: Preserve allocation virtual address for dynam...
Keywords:
Status: NEW
Alias: CVE-2026-90387
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 17:28 UTC by OSIDB Bzimport
Modified: 2026-10-20 11:00 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-09-17 17:28:17 UTC
In the Linux kernel, the following vulnerability has been resolved:

swiotlb: Preserve allocation virtual address for dynamic pools

swiotlb_alloc_tlb() can allocate from the DMA atomic pool when a decrypted
pool is needed from atomic context. With CONFIG_DMA_DIRECT_REMAP, the
atomic pool is backed by remapped virtual addresses, which are not the same
as the direct-map addresses returned by phys_to_virt().

swiotlb_init_io_tlb_pool() currently reconstructs the pool virtual address
from the physical start address. For atomic-pool backed allocations this
stores the wrong address in pool->vaddr. Later, swiotlb_free_tlb() passes
that address to dma_free_from_pool(), which will fail to recognize the
chunk

Pass the virtual address returned by the allocation path into
swiotlb_init_io_tlb_pool(), and store that address in pool->vaddr. This
keeps the pool free path using the same virtual address as the allocator.


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