| The vulnerability, identified as CVE-2021-46917, affects the dmaengine subsystem in the Linux kernel, specifically the idxd (Index DMA) driver. The issue arises from a pre-release silicon erratum workaround that was mistakenly included in the upstream code. This workaround fails to clear the WQCFG registers during workqueue (WQ) reset, leading to potential issues with future devices. |
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| The problem is resolved by using the WQ reset command instead of blasting the MMIO region. This fix ensures that the WQCFG registers are properly cleared, preventing any potential clobbering of registers in future devices. The affected files include `drivers/dma/idxd/device.c`, `drivers/dma/idxd/idxd.h`, and `drivers/dma/idxd/sysfs.c`. |
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| The vulnerability was introduced in kernel version 5.8 with commit da32b28c95a7 and has been fixed in versions 5.10.32, 5.11.16, and 5.12 with commits e5eb9757fe4c, f7dc8f561916, and ea9aadc06a9f, respectively. The Linux kernel CVE team recommends updating to the latest stable kernel version to resolve this issue, as individual changes are not tested or supported in isolation. |
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