cvelist/2024/50xxx/CVE-2024-50275.json
2024-12-14 21:00:54 +00:00

135 lines
8.7 KiB
JSON

{
"data_version": "4.0",
"data_type": "CVE",
"data_format": "MITRE",
"CVE_data_meta": {
"ID": "CVE-2024-50275",
"ASSIGNER": "cve@kernel.org",
"STATE": "PUBLIC"
},
"description": {
"description_data": [
{
"lang": "eng",
"value": "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 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."
}
]
},
"problemtype": {
"problemtype_data": [
{
"description": [
{
"lang": "eng",
"value": "n/a"
}
]
}
]
},
"affects": {
"vendor": {
"vendor_data": [
{
"vendor_name": "Linux",
"product": {
"product_data": [
{
"product_name": "Linux",
"version": {
"version_data": [
{
"version_affected": "<",
"version_name": "cccb78ce89c4",
"version_value": "51d3d80a6dc3"
},
{
"version_value": "not down converted",
"x_cve_json_5_version_data": {
"versions": [
{
"version": "5.13",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.13",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "5.15.174",
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.1.120",
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.6.61",
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
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},
{
"version": "6.11.8",
"lessThanOrEqual": "6.11.*",
"status": "unaffected",
"versionType": "semver"
},
{
"version": "6.12",
"lessThanOrEqual": "*",
"status": "unaffected",
"versionType": "original_commit_for_fix"
}
],
"defaultStatus": "affected"
}
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"references": {
"reference_data": [
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"url": "https://git.kernel.org/stable/c/51d3d80a6dc314982a9a0aeb0961085922a1aa15",
"refsource": "MISC",
"name": "https://git.kernel.org/stable/c/51d3d80a6dc314982a9a0aeb0961085922a1aa15"
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{
"url": "https://git.kernel.org/stable/c/de529504b3274d57caf8f66800b714b0d3ee235a",
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"name": "https://git.kernel.org/stable/c/de529504b3274d57caf8f66800b714b0d3ee235a"
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"url": "https://git.kernel.org/stable/c/51d11ea0250d6ee461987403bbfd4b2abb5613a7",
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"name": "https://git.kernel.org/stable/c/51d11ea0250d6ee461987403bbfd4b2abb5613a7"
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{
"url": "https://git.kernel.org/stable/c/fa9ce027b3ce37a2bb173bf2553b5caa438fd8c9",
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"name": "https://git.kernel.org/stable/c/fa9ce027b3ce37a2bb173bf2553b5caa438fd8c9"
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{
"url": "https://git.kernel.org/stable/c/751ecf6afd6568adc98f2a6052315552c0483d18",
"refsource": "MISC",
"name": "https://git.kernel.org/stable/c/751ecf6afd6568adc98f2a6052315552c0483d18"
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