CVE-2023-53859

What is known

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: [<00000000002b55c0>] arch_ftrace_ops_list_func+0x250/0x258 ([<00000000002b55bc>] arch_ftrace_ops_list_func+0x24c/0x258) [<0000000000f5f0fc>] ftrace_common+0x1c/0x20 [<00000000001044f6>] arch_cpu_idle+0x6/0x28 [<0000000000f4acf6>] default_idle_call+0x76/0x128 [<00000000001cc374>] do_idle+0xf4/0x1b0 [<00000000001cc6ce>] cpu_startup_entry+0x36/0x40 [<0000000000119d00>] smp_start_secondary+0x140/0x150 [<0000000000f5d2ae>] 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.

Business impact

Successful exploitation of CVE-2023-53859, a reported vulnerability affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
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