What’s Vulnerable › Vulnerabilities

CVE-2025-21671: zram: fix potential UAF of zram table

• Severity: high (CVSS 7.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-01-31 · updated 2026-06-17
• Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: zram: fix potential UAF of zram table If zram_meta_alloc failed early, it frees allocated zram->table without setting it NULL. Which will potentially cause zram_meta_free to access the table if user reset an failed and uninitialized device.

Affected products

• Linux kernel: from 6.1.122 before 6.1.127; from 6.6.68 before 6.6.74; from 6.12.7 before 6.12.11 — fixed in 6.1.127, 6.12.11, 6.6.74

How to fix

Upgrade to a fixed version: Linux kernel 6.1.127, 6.12.11, 6.6.74. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/212fe1c0df4a150fb6298db2cfff267ceaba5402
• https://git.kernel.org/stable/c/571d3f6045cd3a6d9f6aec33b678f3ffe97582ef
• https://git.kernel.org/stable/c/902ef8f16d5ca77edc77c30656be54186c1e99b7
• https://git.kernel.org/stable/c/fe3de867f94819ba0f28e035c0b0182150147d95
• https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html

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