Bug 2425121 (CVE-2023-54145)

Summary: CVE-2023-54145 kernel: Linux kernel: BPF verifier log truncation via crafted user input
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A flaw was found in the Linux kernel's Berkeley Packet Filter (BPF) verifier log. A local user can exploit this by providing excessively long BPF Type Format (BTF) names or BTF.ext source code line strings. This can lead to the truncation of a single verifier log line, potentially obscuring important debugging information. While the kernel code continues to function correctly, this issue represents a minor denial of service affecting the logging mechanism.
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Description OSIDB Bzimport 2025-12-24 14:04:28 UTC 
In the Linux kernel, the following vulnerability has been resolved:

bpf: drop unnecessary user-triggerable WARN_ONCE in verifierl log

It's trivial for user to trigger "verifier log line truncated" warning,
as verifier has a fixed-sized buffer of 1024 bytes (as of now), and there are at
least two pieces of user-provided information that can be output through
this buffer, and both can be arbitrarily sized by user:
  - BTF names;
  - BTF.ext source code lines strings.

Verifier log buffer should be properly sized for typical verifier state
output. But it's sort-of expected that this buffer won't be long enough
in some circumstances. So let's drop the check. In any case code will
work correctly, at worst truncating a part of a single line output.
Comment 1 Alexander B 2025-12-25 00:57:46 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122424-CVE-2023-54145-421d@gregkh/T