{
  "threat_severity" : "Low",
  "public_date" : "2025-12-09T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: s390/idle: mark arch_cpu_idle() noinstr",
    "id" : "2420340",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2420340"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-166",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\ns390/idle: mark arch_cpu_idle() noinstr\nlinux-next commit (\"cpuidle: tracing: Warn about !rcu_is_watching()\")\nadds a new warning which hits on s390's arch_cpu_idle() function:\nRCU not on for: arch_cpu_idle+0x0/0x28\nWARNING: CPU: 2 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x24c/0x258\nModules linked in:\nCPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.2.0-rc6-next-20230202 #4\nHardware name: IBM 8561 T01 703 (z/VM 7.3.0)\nKrnl PSW : 0404d00180000000 00000000002b55c0 (arch_ftrace_ops_list_func+0x250/0x258)\nR:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:1 PM:0 RI:0 EA:3\nKrnl GPRS: c0000000ffffbfff 0000000080000002 0000000000000026 0000000000000000\n0000037ffffe3a28 0000037ffffe3a20 0000000000000000 0000000000000000\n0000000000000000 0000000000f4acf6 00000000001044f0 0000037ffffe3cb0\n0000000000000000 0000000000000000 00000000002b55bc 0000037ffffe3bb8\nKrnl Code: 00000000002b55b0: c02000840051        larl    %r2,0000000001335652\n00000000002b55b6: c0e5fff512d1        brasl   %r14,0000000000157b58\n#00000000002b55bc: af000000            mc      0,0\n>00000000002b55c0: a7f4ffe7            brc     15,00000000002b558e\n00000000002b55c4: 0707                bcr     0,%r7\n00000000002b55c6: 0707                bcr     0,%r7\n00000000002b55c8: eb6ff0480024        stmg    %r6,%r15,72(%r15)\n00000000002b55ce: b90400ef            lgr     %r14,%r15\nCall Trace:\n[<00000000002b55c0>] arch_ftrace_ops_list_func+0x250/0x258\n([<00000000002b55bc>] arch_ftrace_ops_list_func+0x24c/0x258)\n[<0000000000f5f0fc>] ftrace_common+0x1c/0x20\n[<00000000001044f6>] arch_cpu_idle+0x6/0x28\n[<0000000000f4acf6>] default_idle_call+0x76/0x128\n[<00000000001cc374>] do_idle+0xf4/0x1b0\n[<00000000001cc6ce>] cpu_startup_entry+0x36/0x40\n[<0000000000119d00>] smp_start_secondary+0x140/0x150\n[<0000000000f5d2ae>] restart_int_handler+0x6e/0x90\nMark arch_cpu_idle() noinstr like all other architectures with\nCONFIG_ARCH_WANTS_NO_INSTR (should) have it to fix this.", "A kernel warning vulnerability was found in the s390 architecture idle handling in the Linux kernel. The arch_cpu_idle() function was not marked as noinstr (no instrumentation), causing RCU and tracing warnings when ftrace is enabled. This can trigger kernel warnings and potential issues with tracing in idle paths on s390 systems." ],
  "statement" : "This is an instrumentation marking issue in s390 idle handling that causes kernel warnings. The impact is limited to s390 architecture systems and primarily affects tracing/debugging scenarios.",
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2025-05-13T00:00:00Z",
    "advisory" : "RHSA-2025:6966",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-570.12.1.el9_6"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2023-53859\nhttps://nvd.nist.gov/vuln/detail/CVE-2023-53859\nhttps://lore.kernel.org/linux-cve-announce/2025120904-CVE-2023-53859-1c16@gregkh/T" ],
  "name" : "CVE-2023-53859",
  "csaw" : false
}