Executive brief
The Linux kernel's OMAP SSI (Synchronous Serial Interface) driver failed to properly initialize the DMA mask for its controller device, which is a component used for high-speed serial data transfer in embedded systems. Following hardening changes to the kernel's DMA subsystem, this missing initialization could cause the driver to crash or malfunction when performing DMA operations, disrupting device functionality.
Technical details
This is a resource initialization vulnerability in the OMAP SSI controller driver (drivers/hsi/controllers/omap_ssi_core.c). The driver allocates a synthetic HSI controller device via hsi_alloc_controller() that bypasses the normal platform device initialization, leaving the embedded struct device without a DMA mask. Recent DMA API hardening changes (specifically the fix for NULL pointer dereference in dma-direct) now enforce the presence of a valid dma_mask before allowing DMA operations. An attacker with local access or a malicious kernel module could trigger DMA operations that would cause a kernel panic or warning. The fix explicitly initializes the dma_mask field and sets it to support 32-bit DMA addressing via dma_set_mask_and_coherent(), matching the hardware capabilities.
Affected products
- Linux Linux kernel Multiple versions, patched in stable releases including 4.x, 5.x, 6.x, and 7.x series
Timeline
- 2026-09-11: disclosed: CVE-2026-89594 published
- 2026-09-07: patched: Fix committed to stable kernel tree by Greg Kroah-Hartman