{"id":"CVE-2026-23114","summary":"arm64/fpsimd: ptrace: Fix SVE writes on !SME systems","details":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/fpsimd: ptrace: Fix SVE writes on !SME systems\n\nWhen SVE is supported but SME is not supported, a ptrace write to the\nNT_ARM_SVE regset can place the tracee into an invalid state where\n(non-streaming) SVE register data is stored in FP_STATE_SVE format but\nTIF_SVE is clear. This can result in a later warning from\nfpsimd_restore_current_state(), e.g.\n\n  WARNING: CPU: 0 PID: 7214 at arch/arm64/kernel/fpsimd.c:383 fpsimd_restore_current_state+0x50c/0x748\n\nWhen this happens, fpsimd_restore_current_state() will set TIF_SVE,\nplacing the task into the correct state. This occurs before any other\ncheck of TIF_SVE can possibly occur, as other checks of TIF_SVE only\nhappen while the FPSIMD/SVE/SME state is live. Thus, aside from the\nwarning, there is no functional issue.\n\nThis bug was introduced during rework to error handling in commit:\n\n  9f8bf718f2923 (\"arm64/fpsimd: ptrace: Gracefully handle errors\")\n\n... where the setting of TIF_SVE was moved into a block which is only\nexecuted when system_supports_sme() is true.\n\nFix this by removing the system_supports_sme() check. This ensures that\nTIF_SVE is set for (SVE-formatted) writes to NT_ARM_SVE, at the cost of\nunconditionally manipulating the tracee's saved svcr value. The\nmanipulation of svcr is benign and inexpensive, and we already do\nsimilar elsewhere (e.g. during signal handling), so I don't think it's\nworth guarding this with system_supports_sme() checks.\n\nAside from the above, there is no functional change. The 'type' argument\nto sve_set_common() is only set to ARM64_VEC_SME (in ssve_set())) when\nsystem_supports_sme(), so the ARM64_VEC_SME case in the switch statement\nis still unreachable when !system_supports_sme(). When\nCONFIG_ARM64_SME=n, the only caller of sve_set_common() is sve_set(),\nand the compiler can constant-fold for the case where type is\nARM64_VEC_SVE, removing the logic for other cases.","modified":"2026-07-11T03:54:03.655544326Z","published":"2026-02-14T15:09:47.048Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23114.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/128a7494a9f15aad60cc6b7e3546bf481ac54a13"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4f39984176e7edcaba3432b6c649c6fe93bf2f80"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23114.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-23114"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9f8bf718f29230e38a048d08fc3063e316cd60c1"},{"fixed":"4f39984176e7edcaba3432b6c649c6fe93bf2f80"},{"fixed":"128a7494a9f15aad60cc6b7e3546bf481ac54a13"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23114.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.8"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23114.json"}}],"schema_version":"1.7.5"}