CVE-2023-53713arm64: sme: Use STR P to clear FFR context field in streaming SVE mode
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Deferred
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 9f5848665788a0f07bc175cb2cdd06d367b7556e before 97669214944e80d3756657c21c4f286f3da6a423; from 9f5848665788a0f07bc175cb2cdd06d367b7556e before 8769a62faacbbb6cac5e35d9047ce445183d4e9f; from 9f5848665788a0f07bc175cb2cdd06d367b7556e before 1403a899153a12d93fd510e463fd6d0eafba4336; from 9f5848665788a0f07bc175cb2cdd06d367b7556e before 893b24181b4c4bf1fa2841b1ed192e5413a97cb1 | CNA record |
References
- https://git.kernel.org/stable/c/97669214944e80d3756657c21c4f286f3da6a423
- https://git.kernel.org/stable/c/8769a62faacbbb6cac5e35d9047ce445183d4e9f
- https://git.kernel.org/stable/c/1403a899153a12d93fd510e463fd6d0eafba4336
- https://git.kernel.org/stable/c/893b24181b4c4bf1fa2841b1ed192e5413a97cb1
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.