CVE-2026-90012

9.8 CRITICAL

Published 2026-09-16 · Updated 2026-09-16

AI risk analysis

Summary: This flaw in the Linux kernel's SPI driver allows for potential NULL pointer dereferences or oops conditions due to incorrect handling of DMA mappings during partial transfer failures.
Exploitability: Exploitation requires specific timing and conditions where both TX and RX mappings fail differently, making it moderately difficult but feasible with precise attack vectors.
Blast radius: If exploited, this could lead to system crashes or potential privilege escalation through NULL dereferences in kernel space.
Prioritized remediation: Update to the latest Linux kernel version that includes the fix for this vulnerability.

kerneldmastabilitynull-deref

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: spi: Fix DMA mapping ownership on partial map failure If RX mapping fails after TX mapping succeeds, __spi_map_msg() unmaps TX but leaves tx_sg_mapped set. If TX mapping fails on a later transfer, mappings created for earlier transfers remain active. In both cases, cur_{tx,rx}_dma_dev have not yet been updated because they are assigned only after every transfer has been mapped. The subsequent spi_unmap_msg() may therefore unmap the TX mapping again or release earlier mappings using a NULL or stale device. Using a NULL device can trigger an oops. An empty SG table does not prevent the NULL dereference because dma_unmap_sg_attrs() accesses the device before checking the entry count. Publish both mapping devices before mapping starts and unwind all failures through __spi_unmap_msg(). This clears the mapping flags and releases each mapping once with the device that created it. Publishing the devices before the loop also refreshes them when no transfer needs mapping. No mapping flag is set in that case, so current users do not use the pointers as mapping owners.

CVSS vector

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

All references

Source data: NVD (nvd.nist.gov), public domain. Exploit-DB.ai adds local AI analysis for defensive use only.

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