{"id":"CVE-2024-50275","title":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/sve: Discard stale CPU state when handling SVE traps\n\nThe logic for handling SVE traps manipulates saved FPSIMD/SVE state\nincorrectly, and a race with preemption …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\narm64/sve: Discard stale CPU state when handling SVE traps\n\nThe logic for handling SVE traps manipulates saved FPSIMD/SVE state\nincorrectly, and a race with preemption …","severity":"high","cvss":7.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.13, < 6.6.61","linux_kernel >= 6.7, < 6.11.8","linux_kernel = 6.12"],"patched":["linux_kernel 6.11.8"],"published":"2024-11-19","updated":"2026-10-15","sourceUpdated":"2026-10-15T22:17:59.383","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-50275","references":[{"url":"https://git.kernel.org/stable/c/51d11ea0250d6ee461987403bbfd4b2abb5613a7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/51d3d80a6dc314982a9a0aeb0961085922a1aa15","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/751ecf6afd6568adc98f2a6052315552c0483d18","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/de529504b3274d57caf8f66800b714b0d3ee235a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fa9ce027b3ce37a2bb173bf2553b5caa438fd8c9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"epss":0.00242,"epssPercentile":0.15234,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-15T21:40:35.833561Z"},"ingestedAt":"2026-10-15T22:48:25.440Z","slug":"CVE-2024-50275","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\narm64/sve: Discard stale CPU state when handling SVE traps\n\nThe logic for handling SVE traps manipulates saved FPSIMD/SVE state\nincorrectly, and a race with preemption can result in a task having\nTIF_SVE set and TIF_FOREIGN_FPSTATE clear even though the live CPU state\nis stale (e.g. with SVE traps enabled). This has been observed to result\nin warnings from do_sve_acc() where SVE traps are not expected while\nTIF_SVE is set:\n\n|         if (test_and_set_thread_flag(TIF_SVE))\n|                 WARN_ON(1); /* SVE access shouldn't have trapped */\n\nWarnings of this form have been reported intermittently, e.g.\n\n  https://lore.kernel.org/linux-arm-kernel/CA+G9fYtEGe_DhY2Ms7+L7NKsLYUomGsgqpdBj+QwDLeSg=JhGg@mail.gmail.com/\n  https://lore.kernel.org/linux-arm-kernel/000000000000511e9a060ce5a45c@google.com/\n\nThe race can occur when the SVE trap handler is preempted before and\nafter manipulating the saved FPSIMD/SVE state, starting and ending on\nthe same CPU, e.g.\n\n| void do_sve_acc(unsigned long esr, struct pt_regs *regs)\n| {\n|         // Trap on CPU 0 with TIF_SVE clear, SVE traps enabled\n|         // task->fpsimd_cpu is 0.\n|         // per_cpu_ptr(&fpsimd_last_state, 0) is task.\n|\n|         ...\n|\n|         // Preempted; migrated from CPU 0 to CPU 1.\n|         // TIF_FOREIGN_FPSTATE is set.\n|\n|         get_cpu_fpsimd_context();\n|\n|         if (test_and_set_thread_flag(TIF_SVE))\n|                 WARN_ON(1); /* SVE access shouldn't have trapped */\n|\n|         sve_init_regs() {\n|                 if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {\n|                         ...\n|                 } else {\n|                         fpsimd_to_sve(current);\n|                         current->thread.fp_type = FP_STATE_SVE;\n|                 }\n|         }\n|\n|         put_cpu_fpsimd_context();\n|\n|         // Preempted; migrated from CPU 1 to CPU 0.\n|         // task->fpsimd_cpu is still 0\n|         // If per_cpu_ptr(&fpsimd_last_state, 0) is still task then:\n|         // - Stale HW state is reused (with SVE traps enabled)\n|         // - TIF_FOREIGN_FPSTATE is cleared\n|         // - A return to userspace skips HW state restore\n| }\n\nFix the case where the state is not live and TIF_FOREIGN_FPSTATE is set\nby calling fpsimd_flush_task_state() to detach from the saved CPU\nstate. This ensures that a subsequent context switch will not reuse the\nstale CPU state, and will instead set TIF_FOREIGN_FPSTATE, forcing the\nnew state to be reloaded from memory prior to a return to userspace.\n\n## Affected\n\n- `linux_kernel >= 5.13, < 6.6.61`\n- `linux_kernel >= 6.7, < 6.11.8`\n- `linux_kernel = 6.12`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.11.8`","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":40.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}