Kernel fault via mutex in hard IRQ context
Published Jan 14, 2026 · Updated Jan 14, 2026
NULL-pointer dereference in affected Linux Kernel versions allows local users to trigger a kernel fault through MediaTek vcodec. The vcodec VPU IPI handler uses a sleeping mutex in hard IRQ context while protecting encoder and decoder context lists, allowing an invalid context pointer to reach a NULL dereference. Reachability requires the MediaTek MT8173 video-codec path; mainline reproduction used FFmpeg v4l2m2m decoding through Fluster even when the requested capture format was unsupported.
Summary
What happened
NULL-pointer dereference in affected Linux Kernel versions allows local users to trigger a kernel fault through MediaTek vcodec. The vcodec VPU IPI handler uses a sleeping mutex in hard IRQ context while protecting encoder and decoder context lists, allowing an invalid context pointer to reach a NULL dereference. Reachability requires the MediaTek MT8173 video-codec path; mainline reproduction used FFmpeg v4l2m2m decoding through Fluster even when the requested capture format was unsupported.
The record
- CVE
- CVE-2025-71140
- Published
- Jan 14, 2026
- Updated
- Jan 14, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jan 14, 2026CVE publishedPublication date reported by the CVE source.
- Jan 14, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0a2dc707aa42214f9c4827bd57e344e29a0841d6 <2c1ea6214827041f548279c9eda341eda0cc8351
- Affected versionversion=23aaf824121055ba81b55f75444355bd83c8eb38
- Affected versionversion=41671f0c0182b2bae74ca7e3b0f155559e3e2fc5
- Affected versionversion=51c84a8aac6e3b59af2b0e92ba63cabe2e641a2d
- Affected versionversion=6467cda18c9f9b5f2f9a0aa1e2861c653e41f382 <3e858938b0e659f6ec9ddcf853a87f1c5c3f44e1
- Affected versionversion=6467cda18c9f9b5f2f9a0aa1e2861c653e41f382 <a5844227e0f030d2af2d85d4aed10c5eca6ca176
- Affected versionversion=6467cda18c9f9b5f2f9a0aa1e2861c653e41f382 <b92c19675f632a41af1222027a231bc2b7efa7ed
- Affected versionversion=6.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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