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Linux KernelOperating system · Linux

CVE-2025-39923

MEDIUM · 5.5 CVSS v3.1 Published 2025-10-01
Fix available
A fix is available. Upgrade to 4.10 / 4.15 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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/[email protected]/ [2]: https://lore.kernel.org/r/[email protected]/

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 4.9.104, < 4.10>= 4.14.45, < 4.15>= 4.16.13, < 5.4.300>= 5.5, < 5.10.245>= 5.11, < 5.15.194>= 5.16, < 6.1.153>= 6.2, < 6.6.107>= 6.7, < 6.12.48>= 6.13, < 6.16.8= 6.17
Debian LinuxOperating system
Affected:= 11.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.10 / 4.15 / 5.4.300 or later
Fixed in 4.104.155.4.300
Vendor patch git.kernel.org →
Recommended fix High confidence

Kernel 4.10, 4.15, 5.4.300, or 5.10.245 (depending on which version branch is currently in use); or Debian kernel with backported fix for 11.x

  1. 1. Identify the currently running Linux kernel version using 'uname -r'
  2. 2. For systems running kernel versions >= 4.9.104 and < 4.10: upgrade to kernel 4.10 or later
  3. 3. For systems running kernel versions >= 4.14.45 and < 4.15: upgrade to kernel 4.15 or later
  4. 4. For systems running kernel versions >= 4.16.13 and < 5.4.300: upgrade to kernel 5.4.300 or later
  5. 5. For systems running kernel versions >= 5.5 and < 5.10.245: upgrade to kernel 5.10.245 or later
  6. 6. For Debian 11 systems: apply the vendor patch from the stable commit or upgrade to a newer Debian kernel version that includes this fix
  7. 7. Reboot the system after applying the kernel update
Caveat This fix may break some existing device trees that are missing required properties (clock or num-channels), particularly affecting crypto engine BAM instances; such DTBs will need to be corrected

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

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