# CVE-2025-39728: clk: samsung: Fix UBSAN panic in samsung\_clk\_init()

- Severity: CVSS 5.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-04-18 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.5

## Description

In the Linux kernel, the following vulnerability has been resolved: clk: samsung: Fix UBSAN panic in samsung_clk_init() With UBSAN_ARRAY_BOUNDS=y, I'm hitting the below panic due to dereferencing `ctx->clk_data.hws` before setting `ctx->clk_data.num = nr_clks`. Move that up to fix the crash. UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP <snip> Call trace: samsung_clk_init+0x110/0x124 (P) samsung_clk_init+0x48/0x124 (L) samsung_cmu_register_one+0x3c/0xa0 exynos_arm64_register_cmu+0x54/0x64 __gs101_cmu_top_of_clk_init_declare+0x28/0x60 ...

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/00307934eb94aaa0a99addfb37b9fe206f945004
- https://git.kernel.org/stable/c/d974e177369c034984cece9d7d4fada9f8b9c740
- https://git.kernel.org/stable/c/0fef48f4a70e45a93e73c39023c3a6ea624714d6
- https://git.kernel.org/stable/c/4d29a6dcb51e346595a15b49693eeb728925ca43
- https://git.kernel.org/stable/c/24307866e0ac0a5ddb462e766ceda5e27a6fbbe3
- https://git.kernel.org/stable/c/a1500b98cd81a32fdfb9bc63c33bb9f0c2a0a1bf
- https://git.kernel.org/stable/c/157de9e48007a20c65d02fc0229a16f38134a72d
- https://git.kernel.org/stable/c/d19d7345a7bcdb083b65568a11b11adffe0687af

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Page: https://cve.now/CVE-2025-39728
JSON: https://cve.now/api/v1/entries/CVE-2025-39728
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