PT-2025-4328 · Linux+10 · Linux Kernel+10
Syzbot
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Published
2025-01-09
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Updated
2026-01-29
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CVE-2025-21647
CVSS v3.1
7.1
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel versions prior to 6.6.74
Description
A logic error in the Linux kernel's sched: sch cake component led to an underflow of the per-host bulk flow counters, resulting in an out of bounds memory access. To fix this issue, bounds checks were added to host bulk flow fairness counts. The change also improved code readability by consolidating conditional checks for the flow mode into helper functions. Additionally, the flow quantum calculation was consolidated into a helper function, which may cause the maximum packet size that can be sent while a flow stays sparse to vary by +/- one byte in some cases.
Recommendations
For Linux kernel versions prior to 6.6.74, update to version 6.6.74 or later to resolve the issue. As a temporary workaround, consider restricting access to the vulnerable
sched: sch cake component until a patch is available. However, since a fixed version is available, updating to the latest version is the recommended course of action.Exploit
Fix
Out of bounds Read
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Weakness Enumeration
Related Identifiers
Affected Products
Alt Linux
Almalinux
Astra Linux
Debian
Linuxmint
Linux Kernel
Red Hat
Red Os
Rocky Linux
Suse
Ubuntu