{"id":"CVE-2024-26768","summary":"LoongArch: Change acpi_core_pic[NR_CPUS] to acpi_core_pic[MAX_CORE_PIC]","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nLoongArch: Change acpi_core_pic[NR_CPUS] to acpi_core_pic[MAX_CORE_PIC]\n\nWith default config, the value of NR_CPUS is 64. When HW platform has\nmore then 64 cpus, system will crash on these platforms. MAX_CORE_PIC\nis the maximum cpu number in MADT table (max physical number) which can\nexceed the supported maximum cpu number (NR_CPUS, max logical number),\nbut kernel should not crash. Kernel should boot cpus with NR_CPUS, let\nthe remainder cpus stay in BIOS.\n\nThe potential crash reason is that the array acpi_core_pic[NR_CPUS] can\nbe overflowed when parsing MADT table, and it is obvious that CORE_PIC\nshould be corresponding to physical core rather than logical core, so it\nis better to define the array as acpi_core_pic[MAX_CORE_PIC].\n\nWith the patch, system can boot up 64 vcpus with qemu parameter -smp 128,\notherwise system will crash with the following message.\n\n[    0.000000] CPU 0 Unable to handle kernel paging request at virtual address 0000420000004259, era == 90000000037a5f0c, ra == 90000000037a46ec\n[    0.000000] Oops[#1]:\n[    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-rc2+ #192\n[    0.000000] Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022\n[    0.000000] pc 90000000037a5f0c ra 90000000037a46ec tp 9000000003c90000 sp 9000000003c93d60\n[    0.000000] a0 0000000000000019 a1 9000000003d93bc0 a2 0000000000000000 a3 9000000003c93bd8\n[    0.000000] a4 9000000003c93a74 a5 9000000083c93a67 a6 9000000003c938f0 a7 0000000000000005\n[    0.000000] t0 0000420000004201 t1 0000000000000000 t2 0000000000000001 t3 0000000000000001\n[    0.000000] t4 0000000000000003 t5 0000000000000000 t6 0000000000000030 t7 0000000000000063\n[    0.000000] t8 0000000000000014 u0 ffffffffffffffff s9 0000000000000000 s0 9000000003caee98\n[    0.000000] s1 90000000041b0480 s2 9000000003c93da0 s3 9000000003c93d98 s4 9000000003c93d90\n[    0.000000] s5 9000000003caa000 s6 000000000a7fd000 s7 000000000f556b60 s8 000000000e0a4330\n[    0.000000]    ra: 90000000037a46ec platform_init+0x214/0x250\n[    0.000000]   ERA: 90000000037a5f0c efi_runtime_init+0x30/0x94\n[    0.000000]  CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)\n[    0.000000]  PRMD: 00000000 (PPLV0 -PIE -PWE)\n[    0.000000]  EUEN: 00000000 (-FPE -SXE -ASXE -BTE)\n[    0.000000]  ECFG: 00070800 (LIE=11 VS=7)\n[    0.000000] ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0)\n[    0.000000]  BADV: 0000420000004259\n[    0.000000]  PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)\n[    0.000000] Modules linked in:\n[    0.000000] Process swapper (pid: 0, threadinfo=(____ptrval____), task=(____ptrval____))\n[    0.000000] Stack : 9000000003c93a14 9000000003800898 90000000041844f8 90000000037a46ec\n[    0.000000]         000000000a7fd000 0000000008290000 0000000000000000 0000000000000000\n[    0.000000]         0000000000000000 0000000000000000 00000000019d8000 000000000f556b60\n[    0.000000]         000000000a7fd000 000000000f556b08 9000000003ca7700 9000000003800000\n[    0.000000]         9000000003c93e50 9000000003800898 9000000003800108 90000000037a484c\n[    0.000000]         000000000e0a4330 000000000f556b60 000000000a7fd000 000000000f556b08\n[    0.000000]         9000000003ca7700 9000000004184000 0000000000200000 000000000e02b018\n[    0.000000]         000000000a7fd000 90000000037a0790 9000000003800108 0000000000000000\n[    0.000000]         0000000000000000 000000000e0a4330 000000000f556b60 000000000a7fd000\n[    0.000000]         000000000f556b08 000000000eaae298 000000000eaa5040 0000000000200000\n[    0.000000]         ...\n[    0.000000] Call Trace:\n[    0.000000] [\u003c90000000037a5f0c\u003e] efi_runtime_init+0x30/0x94\n[    0.000000] [\u003c90000000037a46ec\u003e] platform_init+0x214/0x250\n[    0.000000] [\u003c90000000037a484c\u003e] setup_arch+0x124/0x45c\n[    0.000000] [\u003c90000000037a0790\u003e] start_kernel+0x90/0x670\n[    0.000000] [\u003c900000000378b0d8\u003e] kernel_entry+0xd8/0xdc","modified":"2026-04-02T10:05:53.224058Z","published":"2024-04-03T17:00:50.135Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26768.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0f6810e39898af2d2cabd9313e4dbc945fb5dfdd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4551b30525cf3d2f026b92401ffe241eb04dfebe"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88e189bd16e5889e44a41b3309558ebab78b9280"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/26xxx/CVE-2024-26768.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-26768"},{"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":"fa96b57c149061f71a70bd6582d995f6424fbbf4"},{"fixed":"88e189bd16e5889e44a41b3309558ebab78b9280"},{"fixed":"0f6810e39898af2d2cabd9313e4dbc945fb5dfdd"},{"fixed":"4551b30525cf3d2f026b92401ffe241eb04dfebe"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-26768.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H"}]}