CVE-2025-39923
What it is
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]/
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 4.10
- Linux Kernel < 4.15
- Linux Kernel < 5.4.300
- Linux Kernel < 5.10.245
- Linux Kernel < 5.15.194
- Linux Kernel < 6.1.153
- Linux Kernel < 6.6.107
- Linux Kernel < 6.12.48
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-39923.md and follow it. Check whether this project is affected by CVE-2025-39923. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/0ff9df758af7022d749718fb6b8385cc5693acf3
- https://git.kernel.org/stable/c/1d98ba204d8a6db0d986c7f1aefaa0dcd1c007a2
- https://git.kernel.org/stable/c/1fc14731f0be4885e60702b9596d14d9a79cf053
- https://git.kernel.org/stable/c/2e257a6125c63350f00dc42b9674f20fd3cf4a9f
- https://git.kernel.org/stable/c/5068b5254812433e841a40886e695633148d362d
- https://git.kernel.org/stable/c/555bd16351a35c79efb029a196975a5a27f7fbc4
- https://git.kernel.org/stable/c/6ac1599d0e78036d9d08efc2f58c2d91f0a3ee4c
- https://git.kernel.org/stable/c/ebf6c7c908e5999531c3517289598f187776124f
References
- https://git.kernel.org/stable/c/0ff9df758af7022d749718fb6b8385cc5693acf3
- https://git.kernel.org/stable/c/1d98ba204d8a6db0d986c7f1aefaa0dcd1c007a2
- https://git.kernel.org/stable/c/1fc14731f0be4885e60702b9596d14d9a79cf053
- https://git.kernel.org/stable/c/2e257a6125c63350f00dc42b9674f20fd3cf4a9f
- https://git.kernel.org/stable/c/5068b5254812433e841a40886e695633148d362d
- https://git.kernel.org/stable/c/555bd16351a35c79efb029a196975a5a27f7fbc4
- https://git.kernel.org/stable/c/6ac1599d0e78036d9d08efc2f58c2d91f0a3ee4c
- https://git.kernel.org/stable/c/ebf6c7c908e5999531c3517289598f187776124f
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html