In the Linux kernel, the following vulnerability has been resolved:
dmaengine: qcom: bam_dma: Fix DT error handling for num-channels/ees
When we don't have a clock specified in the device tree, we have no way to
ensure the BAM is on. This is often the case for remotely-controlled or
remotely-powered BAM instances. In this case, we need to read num-channels
from the DT to have all the necessary information to complete probing.
However, at the moment invalid device trees without clock and without
num-channels still continue probing, because the error handling is missing
return statements. The driver will then later try to read the number of
channels from the registers. This is unsafe, because it relies on boot
firmware and lucky timing to succeed. Unfortunately, the lack of proper
error handling here has been abused for several Qualcomm SoCs upstream,
causing early boot crashes in several situations [1, 2].
Avoid these early crashes by erroring out when any of the required DT
properties are missing. Note that this will break some of the existing DTs
upstream (mainly BAM instances related to the crypto engine). However,
clearly these DTs have never been tested properly, since the error in the
kernel log was just ignored. It's safer to disable the crypto engine for
these broken DTBs.
[1]: https://lore.kernel.org/r/CY01EKQVWE36.B9X5TDXAREPF@fairphone.com/
[2]: https://lore.kernel.org/r/20230626145959.646747-1-krzysztof.kozlowski@linaro.org/
Metrics
Affected Vendors & Products
References
History
Thu, 02 Oct 2025 13:45:00 +0000
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Thu, 02 Oct 2025 09:00:00 +0000
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Linux linux Kernel |
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Vendors & Products |
Linux
Linux linux Kernel |
Wed, 01 Oct 2025 08:15:00 +0000
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Description | In the Linux kernel, the following vulnerability has been resolved: dmaengine: qcom: bam_dma: Fix DT error handling for num-channels/ees When we don't have a clock specified in the device tree, we have no way to ensure the BAM is on. This is often the case for remotely-controlled or remotely-powered BAM instances. In this case, we need to read num-channels from the DT to have all the necessary information to complete probing. However, at the moment invalid device trees without clock and without num-channels still continue probing, because the error handling is missing return statements. The driver will then later try to read the number of channels from the registers. This is unsafe, because it relies on boot firmware and lucky timing to succeed. Unfortunately, the lack of proper error handling here has been abused for several Qualcomm SoCs upstream, causing early boot crashes in several situations [1, 2]. Avoid these early crashes by erroring out when any of the required DT properties are missing. Note that this will break some of the existing DTs upstream (mainly BAM instances related to the crypto engine). However, clearly these DTs have never been tested properly, since the error in the kernel log was just ignored. It's safer to disable the crypto engine for these broken DTBs. [1]: https://lore.kernel.org/r/CY01EKQVWE36.B9X5TDXAREPF@fairphone.com/ [2]: https://lore.kernel.org/r/20230626145959.646747-1-krzysztof.kozlowski@linaro.org/ | |
Title | dmaengine: qcom: bam_dma: Fix DT error handling for num-channels/ees | |
References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-02T13:26:52.384Z
Reserved: 2025-04-16T07:20:57.147Z
Link: CVE-2025-39923

No data.

Status : Received
Published: 2025-10-01T08:15:35.610
Modified: 2025-10-02T14:15:44.837
Link: CVE-2025-39923

No data.

Updated: 2025-10-02T08:40:11Z