CVE-2023-53859

EPSS 0.0%
  • Published: 2025-12-09T16:17:26.630

In the Linux kernel, the following vulnerability has been resolved:

s390/idle: mark arch_cpu_idle() noinstr

linux-next commit (“cpuidle: tracing: Warn about !rcu_is_watching()”)
adds a new warning which hits on s390’s arch_cpu_idle() function:

RCU not on for: arch_cpu_idle+0x0/0x28
WARNING: CPU: 2 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x24c/0x258
Modules linked in:
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.2.0-rc6-next-20230202 #4
Hardware name: IBM 8561 T01 703 (z/VM 7.3.0)
Krnl PSW : 0404d00180000000 00000000002b55c0 (arch_ftrace_ops_list_func+0x250/0x258)
R: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
Krnl GPRS: c0000000ffffbfff 0000000080000002 0000000000000026 0000000000000000
0000037ffffe3a28 0000037ffffe3a20 0000000000000000 0000000000000000
0000000000000000 0000000000f4acf6 00000000001044f0 0000037ffffe3cb0
0000000000000000 0000000000000000 00000000002b55bc 0000037ffffe3bb8
Krnl Code: 00000000002b55b0: c02000840051 larl %r2,0000000001335652
00000000002b55b6: c0e5fff512d1 brasl %r14,0000000000157b58
#00000000002b55bc: af000000 mc 0,0
>00000000002b55c0: a7f4ffe7 brc 15,00000000002b558e
00000000002b55c4: 0707 bcr 0,%r7
00000000002b55c6: 0707 bcr 0,%r7
00000000002b55c8: eb6ff0480024 stmg %r6,%r15,72(%r15)
00000000002b55ce: b90400ef lgr %r14,%r15
Call Trace:
[] arch_ftrace_ops_list_func+0x250/0x258
([] arch_ftrace_ops_list_func+0x24c/0x258)
[] ftrace_common+0x1c/0x20
[] arch_cpu_idle+0x6/0x28
[] default_idle_call+0x76/0x128
[] do_idle+0xf4/0x1b0
[] cpu_startup_entry+0x36/0x40
[] smp_start_secondary+0x140/0x150
[] restart_int_handler+0x6e/0x90

Mark arch_cpu_idle() noinstr like all other architectures with
CONFIG_ARCH_WANTS_NO_INSTR (should) have it to fix this.

Related CVE by CWE

No related CWE found.

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How to fix CVE-2023-53859

CVE-2023-53859 is a unknown severity vulnerability affecting the affected product.

Description: In the Linux kernel, the following vulnerability has been resolved: s390/idle: mark arch_cpu_idle() noinstr linux-next commit (“cpuidle: tracing: Warn about !rcu_is_watching()”) adds a new warning which hits on s390’s arch_cpu_idle() function: RCU not on for: arch_cpu_idle+0x0/0x28 WARNING: CPU: 2 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x24c/0x258 Modules linked in: CPU: 2 PID: 0 Comm: swapper/2 Not tainted […]

Exploit Difficulty: HARD
⏱️ Time to exploit: > 4 hours
🛠️ Required skills: Advanced security expertise
💰 Public exploits: Rare or not public

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

HARD
⏱️ Time to Exploit: > 4 hours
🛠️ Skills Required: Advanced security expertise
💰 Public Exploits: Rare or not public

Vulnerability Timeline

Dec 09, 2025
Vulnerability Published

CVE details first published to NVD database

Dec 09, 2025
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.