{"id":"CVE-2026-93266","title":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: RSI: fix field-spanning write warning in attestation token init\n\nThe challenge is passed in registers a1 through a8","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64: RSI: fix field-spanning write warning in attestation token init\n\nThe challenge is passed in registers a1 through a8. However, copying to\n&regs.a1 makes FORTIFY t…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= b880a80011f56880f32bde47fc6af313359f926b < e505092cb200d430d5b8d8d3e926d45f29474ba3","Linux >= b880a80011f56880f32bde47fc6af313359f926b < d29a8ee271da17b5e32d7a76a9c78d43f66447ca","Linux >= b880a80011f56880f32bde47fc6af313359f926b < 221049874b6a78c7d87bc826581b0695cd338e2b","Linux 6.13"],"published":"2026-09-24","updated":"2026-09-24","sourceUpdated":"2026-09-24T16:17:23.453","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-93266","references":[{"url":"https://git.kernel.org/stable/c/221049874b6a78c7d87bc826581b0695cd338e2b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d29a8ee271da17b5e32d7a76a9c78d43f66447ca","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e505092cb200d430d5b8d8d3e926d45f29474ba3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-24T16:47:15.837Z","slug":"CVE-2026-93266","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\narm64: RSI: fix field-spanning write warning in attestation token init\n\nThe challenge is passed in registers a1 through a8. However, copying to\n&regs.a1 makes FORTIFY treat the destination as the single a1 field,\nresulting in a field-spanning write warning. [1]\n\nOverlay the SMCCC register structure with an RSI-specific argument\nlayout and copy the challenge into an explicit 64-byte array. This keeps\nthe existing a1-a8 argument encoding while giving the copy a correctly\nsized destination object.\n\n[1]\nmemcpy: detected field-spanning write (size 64) of single field \"&regs.a1\" at ./arch/arm64/include/asm/rsi_cmds.h:119 (size 8)\nWARNING: ./arch/arm64/include/asm/rsi_cmds.h:119 at rsi_attestation_token_init+0xdc/0xf8 [arm_cca_guest], CPU#0: cat/3314\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}