CVE-2023-53859

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> s390/idle: mark arch_cpu_idle() noinstr<br /> <br /> linux-next commit ("cpuidle: tracing: Warn about !rcu_is_watching()")<br /> adds a new warning which hits on s390&amp;#39;s arch_cpu_idle() function:<br /> <br /> RCU not on for: arch_cpu_idle+0x0/0x28<br /> WARNING: CPU: 2 PID: 0 at include/linux/trace_recursion.h:162 arch_ftrace_ops_list_func+0x24c/0x258<br /> Modules linked in:<br /> CPU: 2 PID: 0 Comm: swapper/2 Not tainted 6.2.0-rc6-next-20230202 #4<br /> Hardware name: IBM 8561 T01 703 (z/VM 7.3.0)<br /> Krnl PSW : 0404d00180000000 00000000002b55c0 (arch_ftrace_ops_list_func+0x250/0x258)<br /> 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<br /> Krnl GPRS: c0000000ffffbfff 0000000080000002 0000000000000026 0000000000000000<br /> 0000037ffffe3a28 0000037ffffe3a20 0000000000000000 0000000000000000<br /> 0000000000000000 0000000000f4acf6 00000000001044f0 0000037ffffe3cb0<br /> 0000000000000000 0000000000000000 00000000002b55bc 0000037ffffe3bb8<br /> Krnl Code: 00000000002b55b0: c02000840051 larl %r2,0000000001335652<br /> 00000000002b55b6: c0e5fff512d1 brasl %r14,0000000000157b58<br /> #00000000002b55bc: af000000 mc 0,0<br /> &gt;00000000002b55c0: a7f4ffe7 brc 15,00000000002b558e<br /> 00000000002b55c4: 0707 bcr 0,%r7<br /> 00000000002b55c6: 0707 bcr 0,%r7<br /> 00000000002b55c8: eb6ff0480024 stmg %r6,%r15,72(%r15)<br /> 00000000002b55ce: b90400ef lgr %r14,%r15<br /> Call Trace:<br /> [] arch_ftrace_ops_list_func+0x250/0x258<br /> ([] arch_ftrace_ops_list_func+0x24c/0x258)<br /> [] ftrace_common+0x1c/0x20<br /> [] arch_cpu_idle+0x6/0x28<br /> [] default_idle_call+0x76/0x128<br /> [] do_idle+0xf4/0x1b0<br /> [] cpu_startup_entry+0x36/0x40<br /> [] smp_start_secondary+0x140/0x150<br /> [] restart_int_handler+0x6e/0x90<br /> <br /> Mark arch_cpu_idle() noinstr like all other architectures with<br /> CONFIG_ARCH_WANTS_NO_INSTR (should) have it to fix this.