Service interruption via invalid GPIO bit shift
Published May 21, 2024 · Updated May 11, 2026
A shift-out-of-bounds flaw in affected Linux kernel releases allows local users to interrupt service through the wcd934x GPIO driver. The driver's bit-mask expression computes BIT(n - 1), although pins zero through four require BIT(0) through BIT(4), so pin zero produces an invalid negative shift detected by UBSAN. Exploitation requires local low-privileged access and the affected wcd934x GPIO path; the published impact is limited to service interruption.
Summary
What happened
A shift-out-of-bounds flaw in affected Linux kernel releases allows local users to interrupt service through the wcd934x GPIO driver. The driver's bit-mask expression computes BIT(n - 1), although pins zero through four require BIT(0) through BIT(4), so pin zero produces an invalid negative shift detected by UBSAN. Exploitation requires local low-privileged access and the affected wcd934x GPIO path; the published impact is limited to service interruption.
The record
- CVE
- CVE-2021-47263
- Published
- May 21, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- T1499.004
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 21, 2024CVE publishedPublication date reported by the CVE source.
- May 11, 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=5.6
- Affected versionversion=59c324683400b41caa6d85b091e812ee3d5415c3 <dbec64b11c65d74f31427e2b9d5746fbf17bf840
- Affected versionversion=59c324683400b41caa6d85b091e812ee3d5415c3 <dd55331d493b7ea75c5db1f24d6822946fde2862
- Affected versionversion=59c324683400b41caa6d85b091e812ee3d5415c3 <e0b518a2eb44d8a74c19e50f79a8ed393e96d634
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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