Summary
In the Linux kernel, the following vulnerability has been resolved: arm64: sme: Use STR P to...
In the Linux kernel, the following vulnerability has been resolved:
arm64: sme: Use STR P to clear FFR context field in streaming SVE mode
The FFR is a predicate register which can vary between 16 and 256 bits
in size depending upon the configured vector length. When saving the
SVE state in streaming SVE mode, the FFR register is inaccessible and
so commit 9f5848665788 ("arm64/sve: Make access to FFR optional") simply
clears the FFR field of the in-memory context structure. Unfortunately,
it achieves this using an unconditional 8-byte store and so if the SME
vector length is anything other than 64 bytes in size we will either
fail to clear the entire field or, worse, we will corrupt memory
immediately following the structure. This has led to intermittent kfence
splats in CI [1] and can trigger kmalloc Redzone corruption messages
when running the 'fp-stress' kselftest:
| =============================================================================
| BUG kmalloc-1k (Not tainted): kmalloc Redzone overwritten |
|---|
| 0xffff000809bf1e22-0xffff000809bf1e27 @offset=7714. First byte 0x0 instead of 0xcc |
| Allocated in do_sme_acc+0x9c/0x220 age=2613 cpu=1 pid=531 |
| __kmalloc+0x8c/0xcc |
| do_sme_acc+0x9c/0x220 |
| ... |
Replace the 8-byte store with a store of a predicate register which has
been zero-initialised with PFALSE, ensuring that the entire field is
cleared in memory.
[1] https://lore.kernel.org/r/CA+G9fYtU7HsV0R0dp4XEH5xXHSJFw8KyDf5VQrLLfMxWfxQkag@mail.gmail.com
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2023-53713? CVE-2023-53713 is a unknown-severity security vulnerability. No fixed version is listed yet.
- Is there a fix for CVE-2023-53713? No fixed version is listed for CVE-2023-53713 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2023-53713 exploitable, and should I be worried? Whether CVE-2023-53713 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-53713 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.