Kernel-memory disclosure via misindexed DSP stack dump
Published May 21, 2024 · Updated May 11, 2026
Information disclosure in Linux 5.2 through 5.14.9 and 5.15-rc1 through 5.15-rc3 allows local users to read kernel memory. The xtensa_stack function passes stack + i * 4 to hex_dump_to_buffer even though stack is a u32 pointer, advancing four times too far and dumping out-of-bounds words. Exposure requires a DSP oops on an affected Sound Open Firmware Xtensa path; the resulting kernel log discloses stack data without altering it.
Summary
What happened
Information disclosure in Linux 5.2 through 5.14.9 and 5.15-rc1 through 5.15-rc3 allows local users to read kernel memory. The xtensa_stack function passes stack + i * 4 to hex_dump_to_buffer even though stack is a u32 pointer, advancing four times too far and dumping out-of-bounds words. Exposure requires a DSP oops on an affected Sound Open Firmware Xtensa path; the resulting kernel log discloses stack data without altering it.
The record
- CVE
- CVE-2021-47381
- Published
- May 21, 2024
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-209
- 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
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=5.2
- Affected versionversion=e657c18a01c85d2c4ec0e96d52be8ba42b956593 <a6bb576ead074ca6fa3b53cb1c5d4037a23de81b
- Affected versionversion=e657c18a01c85d2c4ec0e96d52be8ba42b956593 <ac4dfccb96571ca03af7cac64b7a0b2952c97f3a
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo